diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4b1fdcdce..56b6371d5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -51,6 +51,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - MRF: New module which handles incoming posts based on their age. By default, all incoming posts that are older than 2 days will be unlisted and not shown to their followers.
 - User notification settings: Add `privacy_option` option.
 - User settings: Add _This account is a_ option.
+- OAuth: admin scopes support (relevant setting: `[:auth, :enforce_oauth_admin_scope_usage]`).
 <details>
   <summary>API Changes</summary>
 
diff --git a/config/config.exs b/config/config.exs
index 4624bded2..6ed800056 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -563,7 +563,10 @@
        base_path: "/oauth",
        providers: ueberauth_providers
 
-config :pleroma, :auth, oauth_consumer_strategies: oauth_consumer_strategies
+config :pleroma,
+       :auth,
+       enforce_oauth_admin_scope_usage: false,
+       oauth_consumer_strategies: oauth_consumer_strategies
 
 config :pleroma, Pleroma.Emails.Mailer, adapter: Swoosh.Adapters.Sendmail, enabled: false
 
diff --git a/config/description.exs b/config/description.exs
index 70e963399..45e4b43f1 100644
--- a/config/description.exs
+++ b/config/description.exs
@@ -2094,6 +2094,15 @@
     type: :group,
     description: "Authentication / authorization settings",
     children: [
+      %{
+        key: :enforce_oauth_admin_scope_usage,
+        type: :boolean,
+        description:
+          "OAuth admin scope requirement toggle. " <>
+            "If `true`, admin actions explicitly demand admin OAuth scope(s) presence in OAuth token " <>
+            "(client app must support admin scopes). If `false` and token doesn't have admin scope(s)," <>
+            "`is_admin` user flag grants access to admin-specific actions."
+      },
       %{
         key: :auth_template,
         type: :string,
diff --git a/docs/API/admin_api.md b/docs/API/admin_api.md
index 2cac317de..b19793150 100644
--- a/docs/API/admin_api.md
+++ b/docs/API/admin_api.md
@@ -2,6 +2,13 @@
 
 Authentication is required and the user must be an admin.
 
+Configuration options:
+ 
+* `[:auth, :enforce_oauth_admin_scope_usage]` — OAuth admin scope requirement toggle.
+    If `true`, admin actions explicitly demand admin OAuth scope(s) presence in OAuth token (client app must support admin scopes).
+    If `false` and token doesn't have admin scope(s), `is_admin` user flag grants access to admin-specific actions.
+    Note that client app needs to explicitly support admin scopes and request them when obtaining auth token.
+
 ## `GET /api/pleroma/admin/users`
 
 ### List users
diff --git a/lib/mix/tasks/pleroma/user.ex b/lib/mix/tasks/pleroma/user.ex
index 0adb78fe3..85c9e4954 100644
--- a/lib/mix/tasks/pleroma/user.ex
+++ b/lib/mix/tasks/pleroma/user.ex
@@ -8,7 +8,6 @@ defmodule Mix.Tasks.Pleroma.User do
   alias Ecto.Changeset
   alias Pleroma.User
   alias Pleroma.UserInviteToken
-  alias Pleroma.Web.OAuth
 
   @shortdoc "Manages Pleroma users"
   @moduledoc File.read!("docs/administration/CLI_tasks/user.md")
@@ -354,8 +353,7 @@ def run(["sign_out", nickname]) do
     start_pleroma()
 
     with %User{local: true} = user <- User.get_cached_by_nickname(nickname) do
-      OAuth.Token.delete_user_tokens(user)
-      OAuth.Authorization.delete_user_authorizations(user)
+      User.global_sign_out(user)
 
       shell_info("#{nickname} signed out from all apps.")
     else
@@ -393,10 +391,7 @@ defp set_moderator(user, value) do
   end
 
   defp set_admin(user, value) do
-    {:ok, user} =
-      user
-      |> Changeset.change(%{is_admin: value})
-      |> User.update_and_set_cache()
+    {:ok, user} = User.admin_api_update(user, %{is_admin: value})
 
     shell_info("Admin status of #{user.nickname}: #{user.is_admin}")
     user
diff --git a/lib/pleroma/config.ex b/lib/pleroma/config.ex
index fcc039710..cadab2f15 100644
--- a/lib/pleroma/config.ex
+++ b/lib/pleroma/config.ex
@@ -65,4 +65,11 @@ def delete(key) do
   def oauth_consumer_strategies, do: get([:auth, :oauth_consumer_strategies], [])
 
   def oauth_consumer_enabled?, do: oauth_consumer_strategies() != []
+
+  def enforce_oauth_admin_scope_usage?, do: !!get([:auth, :enforce_oauth_admin_scope_usage])
+
+  def oauth_admin_scopes(scope) do
+    ["admin:#{scope}"] ++
+      if enforce_oauth_admin_scope_usage?(), do: [], else: [scope]
+  end
 end
diff --git a/lib/pleroma/plugs/oauth_scopes_plug.ex b/lib/pleroma/plugs/oauth_scopes_plug.ex
index a3278dbef..3201fb399 100644
--- a/lib/pleroma/plugs/oauth_scopes_plug.ex
+++ b/lib/pleroma/plugs/oauth_scopes_plug.ex
@@ -6,6 +6,7 @@ defmodule Pleroma.Plugs.OAuthScopesPlug do
   import Plug.Conn
   import Pleroma.Web.Gettext
 
+  alias Pleroma.Config
   alias Pleroma.Plugs.EnsurePublicOrAuthenticatedPlug
 
   @behaviour Plug
@@ -15,6 +16,14 @@ def init(%{scopes: _} = options), do: options
   def call(%Plug.Conn{assigns: assigns} = conn, %{scopes: scopes} = options) do
     op = options[:op] || :|
     token = assigns[:token]
+
+    scopes =
+      if options[:admin] do
+        Config.oauth_admin_scopes(scopes)
+      else
+        scopes
+      end
+
     matched_scopes = token && filter_descendants(scopes, token.scopes)
 
     cond do
diff --git a/lib/pleroma/plugs/user_is_admin_plug.ex b/lib/pleroma/plugs/user_is_admin_plug.ex
index ee808f31f..582fb1f92 100644
--- a/lib/pleroma/plugs/user_is_admin_plug.ex
+++ b/lib/pleroma/plugs/user_is_admin_plug.ex
@@ -5,19 +5,38 @@
 defmodule Pleroma.Plugs.UserIsAdminPlug do
   import Pleroma.Web.TranslationHelpers
   import Plug.Conn
+
   alias Pleroma.User
+  alias Pleroma.Web.OAuth
 
   def init(options) do
     options
   end
 
-  def call(%{assigns: %{user: %User{is_admin: true}}} = conn, _) do
-    conn
+  def call(%{assigns: %{user: %User{is_admin: true}} = assigns} = conn, _) do
+    token = assigns[:token]
+
+    cond do
+      not Pleroma.Config.enforce_oauth_admin_scope_usage?() ->
+        conn
+
+      token && OAuth.Scopes.contains_admin_scopes?(token.scopes) ->
+        # Note: checking for _any_ admin scope presence, not necessarily fitting requested action.
+        #   Thus, controller must explicitly invoke OAuthScopesPlug to verify scope requirements.
+        conn
+
+      true ->
+        fail(conn)
+    end
   end
 
   def call(conn, _) do
+    fail(conn)
+  end
+
+  defp fail(conn) do
     conn
-    |> render_error(:forbidden, "User is not admin.")
-    |> halt
+    |> render_error(:forbidden, "User is not an admin or OAuth admin scope is not granted.")
+    |> halt()
   end
 end
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 694f1f110..6b556e8e1 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -1839,13 +1839,28 @@ defp truncate_field(%{"name" => name, "value" => value}) do
   end
 
   def admin_api_update(user, params) do
-    user
-    |> cast(params, [
-      :is_moderator,
-      :is_admin,
-      :show_role
-    ])
-    |> update_and_set_cache()
+    changeset =
+      cast(user, params, [
+        :is_moderator,
+        :is_admin,
+        :show_role
+      ])
+
+    with {:ok, updated_user} <- update_and_set_cache(changeset) do
+      if user.is_admin && !updated_user.is_admin do
+        # Tokens & authorizations containing any admin scopes must be revoked (revoking all).
+        # This is an extra safety measure (tokens' admin scopes won't be accepted for non-admins).
+        global_sign_out(user)
+      end
+
+      {:ok, updated_user}
+    end
+  end
+
+  @doc "Signs user out of all applications"
+  def global_sign_out(user) do
+    OAuth.Authorization.delete_user_authorizations(user)
+    OAuth.Token.delete_user_tokens(user)
   end
 
   def mascot_update(user, url) do
diff --git a/lib/pleroma/web/admin_api/admin_api_controller.ex b/lib/pleroma/web/admin_api/admin_api_controller.ex
index b003d1f35..0a8a56cd8 100644
--- a/lib/pleroma/web/admin_api/admin_api_controller.ex
+++ b/lib/pleroma/web/admin_api/admin_api_controller.ex
@@ -30,13 +30,13 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["read:accounts"]}
+    %{scopes: ["read:accounts"], admin: true}
     when action in [:list_users, :user_show, :right_get, :invites]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["write:accounts"]}
+    %{scopes: ["write:accounts"], admin: true}
     when action in [
            :get_invite_token,
            :revoke_invite,
@@ -58,35 +58,37 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["read:reports"]} when action in [:list_reports, :report_show]
+    %{scopes: ["read:reports"], admin: true}
+    when action in [:list_reports, :report_show]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["write:reports"]}
+    %{scopes: ["write:reports"], admin: true}
     when action in [:report_update_state, :report_respond]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["read:statuses"]} when action == :list_user_statuses
+    %{scopes: ["read:statuses"], admin: true}
+    when action == :list_user_statuses
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["write:statuses"]}
+    %{scopes: ["write:statuses"], admin: true}
     when action in [:status_update, :status_delete]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["read"]}
+    %{scopes: ["read"], admin: true}
     when action in [:config_show, :migrate_to_db, :migrate_from_db, :list_log]
   )
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["write"]}
+    %{scopes: ["write"], admin: true}
     when action in [:relay_follow, :relay_unfollow, :config_update]
   )
 
diff --git a/lib/pleroma/web/oauth/oauth_controller.ex b/lib/pleroma/web/oauth/oauth_controller.ex
index 2aee8cab2..87acdec97 100644
--- a/lib/pleroma/web/oauth/oauth_controller.ex
+++ b/lib/pleroma/web/oauth/oauth_controller.ex
@@ -222,7 +222,7 @@ def token_exchange(
          {:user_active, true} <- {:user_active, !user.deactivated},
          {:password_reset_pending, false} <-
            {:password_reset_pending, user.password_reset_pending},
-         {:ok, scopes} <- validate_scopes(app, params),
+         {:ok, scopes} <- validate_scopes(app, params, user),
          {:ok, auth} <- Authorization.create_authorization(app, user, scopes),
          {:ok, token} <- Token.exchange_token(app, auth) do
       json(conn, Token.Response.build(user, token))
@@ -471,7 +471,7 @@ defp do_create_authorization(
            {:get_user, (user && {:ok, user}) || Authenticator.get_user(conn)},
          %App{} = app <- Repo.get_by(App, client_id: client_id),
          true <- redirect_uri in String.split(app.redirect_uris),
-         {:ok, scopes} <- validate_scopes(app, auth_attrs),
+         {:ok, scopes} <- validate_scopes(app, auth_attrs, user),
          {:auth_active, true} <- {:auth_active, User.auth_active?(user)} do
       Authorization.create_authorization(app, user, scopes)
     end
@@ -487,12 +487,12 @@ defp get_session_registration_id(%Plug.Conn{} = conn), do: get_session(conn, :re
   defp put_session_registration_id(%Plug.Conn{} = conn, registration_id),
     do: put_session(conn, :registration_id, registration_id)
 
-  @spec validate_scopes(App.t(), map()) ::
+  @spec validate_scopes(App.t(), map(), User.t()) ::
           {:ok, list()} | {:error, :missing_scopes | :unsupported_scopes}
-  defp validate_scopes(app, params) do
+  defp validate_scopes(%App{} = app, params, %User{} = user) do
     params
     |> Scopes.fetch_scopes(app.scopes)
-    |> Scopes.validate(app.scopes)
+    |> Scopes.validate(app.scopes, user)
   end
 
   def default_redirect_uri(%App{} = app) do
diff --git a/lib/pleroma/web/oauth/scopes.ex b/lib/pleroma/web/oauth/scopes.ex
index 48bd14407..5e04652c2 100644
--- a/lib/pleroma/web/oauth/scopes.ex
+++ b/lib/pleroma/web/oauth/scopes.ex
@@ -7,6 +7,9 @@ defmodule Pleroma.Web.OAuth.Scopes do
   Functions for dealing with scopes.
   """
 
+  alias Pleroma.Plugs.OAuthScopesPlug
+  alias Pleroma.User
+
   @doc """
   Fetch scopes from request params.
 
@@ -53,15 +56,36 @@ def to_string(scopes), do: Enum.join(scopes, " ")
   @doc """
   Validates scopes.
   """
-  @spec validate(list() | nil, list()) ::
+  @spec validate(list() | nil, list(), User.t()) ::
           {:ok, list()} | {:error, :missing_scopes | :unsupported_scopes}
-  def validate([], _app_scopes), do: {:error, :missing_scopes}
-  def validate(nil, _app_scopes), do: {:error, :missing_scopes}
+  def validate(blank_scopes, _app_scopes, _user) when blank_scopes in [nil, []],
+    do: {:error, :missing_scopes}
 
-  def validate(scopes, app_scopes) do
-    case Pleroma.Plugs.OAuthScopesPlug.filter_descendants(scopes, app_scopes) do
+  def validate(scopes, app_scopes, %User{} = user) do
+    with {:ok, _} <- ensure_scopes_support(scopes, app_scopes),
+         {:ok, scopes} <- authorize_admin_scopes(scopes, app_scopes, user) do
+      {:ok, scopes}
+    end
+  end
+
+  defp ensure_scopes_support(scopes, app_scopes) do
+    case OAuthScopesPlug.filter_descendants(scopes, app_scopes) do
       ^scopes -> {:ok, scopes}
       _ -> {:error, :unsupported_scopes}
     end
   end
+
+  defp authorize_admin_scopes(scopes, app_scopes, %User{} = user) do
+    if user.is_admin || !contains_admin_scopes?(scopes) || !contains_admin_scopes?(app_scopes) do
+      {:ok, scopes}
+    else
+      {:error, :unsupported_scopes}
+    end
+  end
+
+  def contains_admin_scopes?(scopes) do
+    scopes
+    |> OAuthScopesPlug.filter_descendants(["admin"])
+    |> Enum.any?()
+  end
 end
diff --git a/lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex b/lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex
index a474d41d4..69dfa92e3 100644
--- a/lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex
+++ b/lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex
@@ -7,7 +7,7 @@ defmodule Pleroma.Web.PleromaAPI.EmojiAPIController do
 
   plug(
     OAuthScopesPlug,
-    %{scopes: ["write"]}
+    %{scopes: ["write"], admin: true}
     when action in [
            :create,
            :delete,
diff --git a/test/plugs/user_is_admin_plug_test.exs b/test/plugs/user_is_admin_plug_test.exs
index 136dcc54e..bc6fcd73c 100644
--- a/test/plugs/user_is_admin_plug_test.exs
+++ b/test/plugs/user_is_admin_plug_test.exs
@@ -8,36 +8,116 @@ defmodule Pleroma.Plugs.UserIsAdminPlugTest do
   alias Pleroma.Plugs.UserIsAdminPlug
   import Pleroma.Factory
 
-  test "accepts a user that is admin" do
-    user = insert(:user, is_admin: true)
+  describe "unless [:auth, :enforce_oauth_admin_scope_usage]," do
+    clear_config([:auth, :enforce_oauth_admin_scope_usage]) do
+      Pleroma.Config.put([:auth, :enforce_oauth_admin_scope_usage], false)
+    end
 
-    conn =
-      build_conn()
-      |> assign(:user, user)
+    test "accepts a user that is an admin" do
+      user = insert(:user, is_admin: true)
 
-    ret_conn =
-      conn
-      |> UserIsAdminPlug.call(%{})
+      conn = assign(build_conn(), :user, user)
 
-    assert conn == ret_conn
+      ret_conn = UserIsAdminPlug.call(conn, %{})
+
+      assert conn == ret_conn
+    end
+
+    test "denies a user that isn't an admin" do
+      user = insert(:user)
+
+      conn =
+        build_conn()
+        |> assign(:user, user)
+        |> UserIsAdminPlug.call(%{})
+
+      assert conn.status == 403
+    end
+
+    test "denies when a user isn't set" do
+      conn = UserIsAdminPlug.call(build_conn(), %{})
+
+      assert conn.status == 403
+    end
   end
 
-  test "denies a user that isn't admin" do
-    user = insert(:user)
+  describe "with [:auth, :enforce_oauth_admin_scope_usage]," do
+    clear_config([:auth, :enforce_oauth_admin_scope_usage]) do
+      Pleroma.Config.put([:auth, :enforce_oauth_admin_scope_usage], true)
+    end
 
-    conn =
-      build_conn()
-      |> assign(:user, user)
-      |> UserIsAdminPlug.call(%{})
+    setup do
+      admin_user = insert(:user, is_admin: true)
+      non_admin_user = insert(:user, is_admin: false)
+      blank_user = nil
 
-    assert conn.status == 403
-  end
+      {:ok, %{users: [admin_user, non_admin_user, blank_user]}}
+    end
 
-  test "denies when a user isn't set" do
-    conn =
-      build_conn()
-      |> UserIsAdminPlug.call(%{})
+    test "if token has any of admin scopes, accepts a user that is an admin", %{conn: conn} do
+      user = insert(:user, is_admin: true)
+      token = insert(:oauth_token, user: user, scopes: ["admin:something"])
 
-    assert conn.status == 403
+      conn =
+        conn
+        |> assign(:user, user)
+        |> assign(:token, token)
+
+      ret_conn = UserIsAdminPlug.call(conn, %{})
+
+      assert conn == ret_conn
+    end
+
+    test "if token has any of admin scopes, denies a user that isn't an admin", %{conn: conn} do
+      user = insert(:user, is_admin: false)
+      token = insert(:oauth_token, user: user, scopes: ["admin:something"])
+
+      conn =
+        conn
+        |> assign(:user, user)
+        |> assign(:token, token)
+        |> UserIsAdminPlug.call(%{})
+
+      assert conn.status == 403
+    end
+
+    test "if token has any of admin scopes, denies when a user isn't set", %{conn: conn} do
+      token = insert(:oauth_token, scopes: ["admin:something"])
+
+      conn =
+        conn
+        |> assign(:user, nil)
+        |> assign(:token, token)
+        |> UserIsAdminPlug.call(%{})
+
+      assert conn.status == 403
+    end
+
+    test "if token lacks admin scopes, denies users regardless of is_admin flag",
+         %{users: users} do
+      for user <- users do
+        token = insert(:oauth_token, user: user)
+
+        conn =
+          build_conn()
+          |> assign(:user, user)
+          |> assign(:token, token)
+          |> UserIsAdminPlug.call(%{})
+
+        assert conn.status == 403
+      end
+    end
+
+    test "if token is missing, denies users regardless of is_admin flag", %{users: users} do
+      for user <- users do
+        conn =
+          build_conn()
+          |> assign(:user, user)
+          |> assign(:token, nil)
+          |> UserIsAdminPlug.call(%{})
+
+        assert conn.status == 403
+      end
+    end
   end
 end
diff --git a/test/web/admin_api/admin_api_controller_test.exs b/test/web/admin_api/admin_api_controller_test.exs
index 4148f04bc..23ca7f110 100644
--- a/test/web/admin_api/admin_api_controller_test.exs
+++ b/test/web/admin_api/admin_api_controller_test.exs
@@ -25,6 +25,60 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIControllerTest do
     :ok
   end
 
+  clear_config([:auth, :enforce_oauth_admin_scope_usage]) do
+    Pleroma.Config.put([:auth, :enforce_oauth_admin_scope_usage], false)
+  end
+
+  describe "with [:auth, :enforce_oauth_admin_scope_usage]," do
+    clear_config([:auth, :enforce_oauth_admin_scope_usage]) do
+      Pleroma.Config.put([:auth, :enforce_oauth_admin_scope_usage], true)
+    end
+
+    test "GET /api/pleroma/admin/users/:nickname requires admin:read:accounts or broader scope" do
+      user = insert(:user)
+      admin = insert(:user, is_admin: true)
+      url = "/api/pleroma/admin/users/#{user.nickname}"
+
+      good_token1 = insert(:oauth_token, user: admin, scopes: ["admin"])
+      good_token2 = insert(:oauth_token, user: admin, scopes: ["admin:read"])
+      good_token3 = insert(:oauth_token, user: admin, scopes: ["admin:read:accounts"])
+
+      bad_token1 = insert(:oauth_token, user: admin, scopes: ["read:accounts"])
+      bad_token2 = insert(:oauth_token, user: admin, scopes: ["admin:read:accounts:partial"])
+      bad_token3 = nil
+
+      for good_token <- [good_token1, good_token2, good_token3] do
+        conn =
+          build_conn()
+          |> assign(:user, admin)
+          |> assign(:token, good_token)
+          |> get(url)
+
+        assert json_response(conn, 200)
+      end
+
+      for good_token <- [good_token1, good_token2, good_token3] do
+        conn =
+          build_conn()
+          |> assign(:user, nil)
+          |> assign(:token, good_token)
+          |> get(url)
+
+        assert json_response(conn, :forbidden)
+      end
+
+      for bad_token <- [bad_token1, bad_token2, bad_token3] do
+        conn =
+          build_conn()
+          |> assign(:user, admin)
+          |> assign(:token, bad_token)
+          |> get(url)
+
+        assert json_response(conn, :forbidden)
+      end
+    end
+  end
+
   describe "DELETE /api/pleroma/admin/users" do
     test "single user" do
       admin = insert(:user, is_admin: true)
@@ -98,7 +152,7 @@ test "Create" do
       assert ["lain", "lain2"] -- Enum.map(log_entry.data["subjects"], & &1["nickname"]) == []
     end
 
-    test "Cannot create user with exisiting email" do
+    test "Cannot create user with existing email" do
       admin = insert(:user, is_admin: true)
       user = insert(:user)
 
@@ -129,7 +183,7 @@ test "Cannot create user with exisiting email" do
              ]
     end
 
-    test "Cannot create user with exisiting nickname" do
+    test "Cannot create user with existing nickname" do
       admin = insert(:user, is_admin: true)
       user = insert(:user)
 
@@ -1560,7 +1614,8 @@ test "returns 403 when requested by a non-admin" do
         |> assign(:user, user)
         |> get("/api/pleroma/admin/reports")
 
-      assert json_response(conn, :forbidden) == %{"error" => "User is not admin."}
+      assert json_response(conn, :forbidden) ==
+               %{"error" => "User is not an admin or OAuth admin scope is not granted."}
     end
 
     test "returns 403 when requested by anonymous" do