diff --git a/CHANGELOG.md b/CHANGELOG.md
index a84d5a2196..d8b9490dc3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+### Future
+
+  * Remove `orm_adapter` dependency. Devise now implements its own ORM-specific finders in `Devise::Orm`. [#5823](https://github.com/heartcombo/devise/pull/5823)
+
 ### Unreleased
 
 * enhancements
diff --git a/Gemfile.lock b/Gemfile.lock
index bdf09fcccb..a4d960b06c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -13,7 +13,6 @@ PATH
   specs:
     devise (5.0.1)
       bcrypt (~> 3.0)
-      orm_adapter (~> 0.1)
       railties (>= 7.0)
       responders
       warden (~> 1.2.3)
@@ -187,7 +186,6 @@ GEM
       rack-openid (~> 1.4)
       ruby-openid (~> 2.1, >= 2.1.8)
       version_gem (~> 1.1, >= 1.1.8)
-    orm_adapter (0.5.0)
     ostruct (0.6.3)
     pp (0.6.3)
       prettyprint
diff --git a/app/controllers/devise/registrations_controller.rb b/app/controllers/devise/registrations_controller.rb
index 79e2b0e81c..00fb06749a 100644
--- a/app/controllers/devise/registrations_controller.rb
+++ b/app/controllers/devise/registrations_controller.rb
@@ -44,7 +44,7 @@ def edit
   # We need to use a copy of the resource because we don't want to change
   # the current user in place.
   def update
-    self.resource = resource_class.to_adapter.get!(send(:"current_#{resource_name}").to_key)
+    self.resource = resource_class.devise_find!(send(:"current_#{resource_name}").to_key)
     prev_unconfirmed_email = resource.unconfirmed_email if resource.respond_to?(:unconfirmed_email)
 
     resource_updated = update_resource(resource, account_update_params)
diff --git a/devise.gemspec b/devise.gemspec
index 1caa6aeb39..bcdad24ff8 100644
--- a/devise.gemspec
+++ b/devise.gemspec
@@ -28,7 +28,6 @@ Gem::Specification.new do |s|
   s.required_ruby_version = '>= 2.7.0'
 
   s.add_dependency("warden", "~> 1.2.3")
-  s.add_dependency("orm_adapter", "~> 0.1")
   s.add_dependency("bcrypt", "~> 3.0")
   s.add_dependency("railties", ">= 7.0")
   s.add_dependency("responders")
diff --git a/lib/devise.rb b/lib/devise.rb
index 8e0c85e77d..b46342d35b 100644
--- a/lib/devise.rb
+++ b/lib/devise.rb
@@ -3,7 +3,6 @@
 require 'rails'
 require 'active_support/core_ext/numeric/time'
 require 'active_support/dependencies'
-require 'orm_adapter'
 require 'set'
 require 'securerandom'
 require 'responders'
diff --git a/lib/devise/models/authenticatable.rb b/lib/devise/models/authenticatable.rb
index df964537ea..fdeea649c5 100644
--- a/lib/devise/models/authenticatable.rb
+++ b/lib/devise/models/authenticatable.rb
@@ -227,7 +227,7 @@ def serialize_into_session(record)
         end
 
         def serialize_from_session(key, salt)
-          record = to_adapter.get(key)
+          record = devise_find(key)
           record if record && record.authenticatable_salt == salt
         end
 
@@ -265,7 +265,7 @@ def find_for_authentication(tainted_conditions)
         end
 
         def find_first_by_auth_conditions(tainted_conditions, opts = {})
-          to_adapter.find_first(devise_parameter_filter.filter(tainted_conditions).merge(opts))
+          devise_find_by(devise_parameter_filter.filter(tainted_conditions).merge(opts))
         end
 
         # Find or initialize a record setting an error if it can't be found.
diff --git a/lib/devise/models/recoverable.rb b/lib/devise/models/recoverable.rb
index b17c42aae6..c04f1d7e62 100644
--- a/lib/devise/models/recoverable.rb
+++ b/lib/devise/models/recoverable.rb
@@ -113,7 +113,7 @@ module ClassMethods
         # If a user is not found, return nil
         def with_reset_password_token(token)
           reset_password_token = Devise.token_generator.digest(self, :reset_password_token, token)
-          to_adapter.find_first(reset_password_token: reset_password_token)
+          devise_find_by(reset_password_token: reset_password_token)
         end
 
         # Attempt to find a user by its email. If a record is found, send new
diff --git a/lib/devise/models/rememberable.rb b/lib/devise/models/rememberable.rb
index a66979ad59..e9e3052a81 100644
--- a/lib/devise/models/rememberable.rb
+++ b/lib/devise/models/rememberable.rb
@@ -139,7 +139,7 @@ def serialize_into_cookie(record)
         def serialize_from_cookie(*args)
           id, token, generated_at = *args
 
-          record = to_adapter.get(id)
+          record = devise_find(id)
           record if record && record.remember_me?(token, generated_at)
         end
 
@@ -147,7 +147,7 @@ def serialize_from_cookie(*args)
         def remember_token #:nodoc:
           loop do
             token = Devise.friendly_token
-            break token unless to_adapter.find_first({ remember_token: token })
+            break token unless devise_find_by(remember_token: token)
           end
         end
 
diff --git a/lib/devise/orm.rb b/lib/devise/orm.rb
index 3f3ac86db7..ca0dd848ee 100644
--- a/lib/devise/orm.rb
+++ b/lib/devise/orm.rb
@@ -8,13 +8,47 @@ def self.active_record?(model)
 
     def self.included(model)
       if Devise::Orm.active_record?(model)
-        model.include DirtyTrackingActiveRecordMethods
+        model.include ActiveRecordDirtyTracking
+        model.extend ActiveRecordFinders
       else
-        model.include DirtyTrackingMongoidMethods
+        model.include MongoidDirtyTracking
+        model.extend MongoidFinders
       end
     end
 
-    module DirtyTrackingActiveRecordMethods
+    module ActiveRecordFinders
+      def devise_find(id)
+        id = id.first if id.is_a?(Array)
+        find_by(id: id)
+      end
+
+      def devise_find!(id)
+        id = id.first if id.is_a?(Array)
+        find(id)
+      end
+
+      def devise_find_by(conditions)
+        find_by(conditions)
+      end
+    end
+
+    module MongoidFinders
+      def devise_find(id)
+        id = id.first if id.is_a?(Array)
+        where(id: id).first
+      end
+
+      def devise_find!(id)
+        id = id.first if id.is_a?(Array)
+        find(id)
+      end
+
+      def devise_find_by(conditions)
+        where(conditions).first
+      end
+    end
+
+    module ActiveRecordDirtyTracking
       def devise_email_before_last_save
         email_before_last_save
       end
@@ -40,7 +74,7 @@ def devise_respond_to_and_will_save_change_to_attribute?(attribute)
       end
     end
 
-    module DirtyTrackingMongoidMethods
+    module MongoidDirtyTracking
       def devise_email_before_last_save
         respond_to?(:email_previously_was) ? email_previously_was : email_was
       end
diff --git a/lib/devise/orm/active_record.rb b/lib/devise/orm/active_record.rb
index 0fecf64e3f..419e03b8a9 100644
--- a/lib/devise/orm/active_record.rb
+++ b/lib/devise/orm/active_record.rb
@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require 'orm_adapter/adapters/active_record'
-
 ActiveSupport.on_load(:active_record) do
   extend Devise::Models
 end
diff --git a/lib/devise/orm/mongoid.rb b/lib/devise/orm/mongoid.rb
index 034501eff4..e10e13cd63 100644
--- a/lib/devise/orm/mongoid.rb
+++ b/lib/devise/orm/mongoid.rb
@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
 ActiveSupport.on_load(:mongoid) do
-  require 'orm_adapter/adapters/mongoid'
-
   Mongoid::Document::ClassMethods.send :include, Devise::Models
 end
diff --git a/lib/devise/token_generator.rb b/lib/devise/token_generator.rb
index 9eb74a046a..7b573ccfd6 100644
--- a/lib/devise/token_generator.rb
+++ b/lib/devise/token_generator.rb
@@ -19,7 +19,7 @@ def generate(klass, column)
       loop do
         raw = Devise.friendly_token
         enc = OpenSSL::HMAC.hexdigest(@digest, key, raw)
-        break [raw, enc] unless klass.to_adapter.find_first({ column => enc })
+        break [raw, enc] unless klass.devise_find_by(column => enc)
       end
     end
 
diff --git a/test/integration/registerable_test.rb b/test/integration/registerable_test.rb
index 9289ac6af1..875956f797 100644
--- a/test/integration/registerable_test.rb
+++ b/test/integration/registerable_test.rb
@@ -19,7 +19,7 @@ class RegistrationTest < Devise::IntegrationTest
     assert warden.authenticated?(:admin)
     assert_current_url "/admin_area/home"
 
-    admin = Admin.to_adapter.find_first(order: [:id, :desc])
+    admin = Admin.order(id: :desc).first
     assert_equal 'new_user@test.com', admin.email
   end
 
@@ -68,7 +68,7 @@ def user_sign_up
 
     assert_not warden.authenticated?(:user)
 
-    user = User.to_adapter.find_first(order: [:id, :desc])
+    user = User.order(id: :desc).first
     assert_equal 'new_user@test.com', user.email
     assert_not user.confirmed?
   end
@@ -110,7 +110,7 @@ def user_sign_up
     assert_contain "Email is invalid"
     assert_contain %r{Password confirmation doesn['’]t match Password}
     assert_contain "2 errors prohibited"
-    assert_nil User.to_adapter.find_first
+    assert_nil User.first
 
     assert_not warden.authenticated?(:user)
   end
@@ -154,7 +154,7 @@ def user_sign_up
     assert_current_url '/'
     assert_contain 'Your account has been updated successfully.'
 
-    assert_equal "user.new@example.com", User.to_adapter.find_first.email
+    assert_equal "user.new@example.com", User.first.email
   end
 
   test 'a signed in user should still be able to use the website after changing their password' do
@@ -216,7 +216,7 @@ def user_sign_up
       assert_contain 'Your account has been updated successfully.'
 
       assert warden.authenticated?(:user)
-      assert_equal "user.new@example.com", User.to_adapter.find_first.email
+      assert_equal "user.new@example.com", User.first.email
     end
   end
 
@@ -232,7 +232,7 @@ def user_sign_up
     assert_contain 'user@test.com'
     assert_have_selector 'form input[value="user.new@example.com"]'
 
-    assert_equal "user@test.com", User.to_adapter.find_first.email
+    assert_equal "user@test.com", User.first.email
   end
 
   test 'a signed in user should be able to edit their password' do
@@ -247,7 +247,7 @@ def user_sign_up
     assert_current_url '/'
     assert_contain 'Your account has been updated successfully.'
 
-    assert User.to_adapter.find_first.valid_password?('pass1234')
+    assert User.first.valid_password?('pass1234')
   end
 
   test 'a signed in user should not be able to edit their password with invalid confirmation' do
@@ -260,7 +260,7 @@ def user_sign_up
     click_button 'Update'
 
     assert_contain %r{Password confirmation doesn['’]t match Password}
-    assert_not User.to_adapter.find_first.valid_password?('pas123')
+    assert_not User.first.valid_password?('pas123')
   end
 
   test 'a signed in user should see a warning about minimum password length' do
@@ -276,7 +276,7 @@ def user_sign_up
     click_button "Cancel my account"
     assert_contain "Bye! Your account has been successfully cancelled. We hope to see you again soon."
 
-    assert_empty User.to_adapter.find_all
+    assert_empty User.all
   end
 
   test 'a user should be able to cancel sign up by deleting data in the session' do
@@ -303,7 +303,7 @@ def user_sign_up
     assert_response :success
     assert_includes response.body, '{"admin":{'
 
-    admin = Admin.to_adapter.find_first(order: [:id, :desc])
+    admin = Admin.order(id: :desc).first
     assert_equal 'new_user@test.com', admin.email
   end
 
@@ -312,7 +312,7 @@ def user_sign_up
     assert_response :success
     assert_includes response.body, '{"user":{'
 
-    user = User.to_adapter.find_first(order: [:id, :desc])
+    user = User.order(id: :desc).first
     assert_equal 'new_user@test.com', user.email
   end
 
@@ -340,7 +340,7 @@ def user_sign_up
     sign_in_as_user
     delete user_registration_path(format: 'json')
     assert_response :success
-    assert_equal 0, User.to_adapter.find_all.size
+    assert_equal 0, User.all.size
   end
 end
 
@@ -355,7 +355,7 @@ class ReconfirmableRegistrationTest < Devise::IntegrationTest
 
     assert_current_url '/admin_area/home'
     assert_contain 'but we need to verify your new email address'
-    assert_equal 'admin.new@example.com', Admin.to_adapter.find_first.unconfirmed_email
+    assert_equal 'admin.new@example.com', Admin.first.unconfirmed_email
 
     get edit_admin_registration_path
     assert_contain 'Currently waiting confirmation for: admin.new@example.com'
@@ -373,7 +373,7 @@ class ReconfirmableRegistrationTest < Devise::IntegrationTest
     assert_current_url '/admin_area/home'
     assert_contain 'Your account has been updated successfully.'
 
-    assert Admin.to_adapter.find_first.valid_password?('pas123')
+    assert Admin.first.valid_password?('pas123')
   end
 
   test 'a signed in admin should not see a reconfirmation message if they did not change their email, despite having an unconfirmed email' do
@@ -393,7 +393,7 @@ class ReconfirmableRegistrationTest < Devise::IntegrationTest
     assert_current_url '/admin_area/home'
     assert_contain 'Your account has been updated successfully.'
 
-    assert_equal "admin.new@example.com", Admin.to_adapter.find_first.unconfirmed_email
-    assert Admin.to_adapter.find_first.valid_password?('pas123')
+    assert_equal "admin.new@example.com", Admin.first.unconfirmed_email
+    assert Admin.first.valid_password?('pas123')
   end
 end
diff --git a/test/models/rememberable_test.rb b/test/models/rememberable_test.rb
index 8b83172120..1e83b50f27 100644
--- a/test/models/rememberable_test.rb
+++ b/test/models/rememberable_test.rb
@@ -21,7 +21,7 @@ def create_resource
   test 'remember_me should not generate a new token if valid token exists' do
     user = create_user
     user.singleton_class.send(:attr_accessor, :remember_token)
-    User.to_adapter.expects(:find_first).returns(nil)
+    User.expects(:devise_find_by).returns(nil)
 
     user.remember_me!
     existing_token = user.remember_token
@@ -40,7 +40,7 @@ def create_resource
   test 'can generate remember token' do
     user = create_user
     user.singleton_class.send(:attr_accessor, :remember_token)
-    User.to_adapter.expects(:find_first).returns(nil)
+    User.expects(:devise_find_by).returns(nil)
     user.remember_me!
     assert user.remember_token
   end
diff --git a/test/rails_app/app/controllers/users/omniauth_callbacks_controller.rb b/test/rails_app/app/controllers/users/omniauth_callbacks_controller.rb
index f5327fbd7b..f39cc59d07 100644
--- a/test/rails_app/app/controllers/users/omniauth_callbacks_controller.rb
+++ b/test/rails_app/app/controllers/users/omniauth_callbacks_controller.rb
@@ -8,7 +8,7 @@ def facebook
   end
 
   def sign_in_facebook
-    user = User.to_adapter.find_first(email: 'user@test.com')
+    user = User.devise_find_by(email: 'user@test.com')
     user.remember_me = true
     sign_in user
     render body: ""