diff --git a/changelog/new_deprecated_http_status_names_cop.md b/changelog/new_deprecated_http_status_names_cop.md
new file mode 100644
index 0000000000..d52b47a873
--- /dev/null
+++ b/changelog/new_deprecated_http_status_names_cop.md
@@ -0,0 +1 @@
+* [#1520](https://github.com/rubocop/rubocop-rails/pull/1520): New `Rails/DeprecatedHttpStatusNames` cop. ([@tuxagon][])
diff --git a/config/default.yml b/config/default.yml
index 74bebd3142..82fb968010 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -394,6 +394,14 @@ Rails/DeprecatedActiveModelErrorsMethods:
   VersionAdded: '2.14'
   VersionChanged: '2.18'
 
+Rails/DeprecatedHttpStatusNames:
+  Description: 'Use the new HTTP status names instead of deprecated ones.'
+  Enabled: pending
+  Severity: warning
+  VersionAdded: '<<next>>'
+  Include:
+    - '**/app/controllers/**/*.rb'
+
 Rails/DotSeparatedKeys:
   Description: 'Enforces the use of dot-separated keys instead of `:scope` options in `I18n` translation methods.'
   StyleGuide: 'https://rails.rubystyle.guide/#dot-separated-keys'
diff --git a/lib/rubocop/cop/rails/deprecated_http_status_names.rb b/lib/rubocop/cop/rails/deprecated_http_status_names.rb
new file mode 100644
index 0000000000..ac9796a4be
--- /dev/null
+++ b/lib/rubocop/cop/rails/deprecated_http_status_names.rb
@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Rails
+      # Enforces the use of the current HTTP status names instead of deprecated ones.
+      #
+      # @example
+      #   # bad
+      #   render json: { error: "Invalid data" }, status: :unprocessable_entity
+      #   head :payload_too_large
+      #
+      #   # good
+      #   render json: { error: "Invalid data" }, status: :unprocessable_content
+      #   head :content_too_large
+      #
+      class DeprecatedHttpStatusNames < Base
+        extend AutoCorrector
+
+        requires_gem 'rack', '>= 3.1.0'
+
+        RESTRICT_ON_SEND = %i[render redirect_to head assert_response assert_redirected_to].freeze
+
+        DEPRECATED_STATUSES = {
+          unprocessable_entity: :unprocessable_content,
+          payload_too_large: :content_too_large
+        }.freeze
+
+        MSG = 'Use `:%<preferred>s` instead of `:%<deprecated>s`. The `:%<deprecated>s` status is deprecated.'
+
+        def_node_matcher :status_method_call, <<~PATTERN
+          {
+            (send nil? {:render :redirect_to} _ $hash)
+            (send nil? {:render :redirect_to} $hash)
+            (send nil? {:head :assert_response} $_ ...)
+            (send nil? :assert_redirected_to _ $hash ...)
+            (send nil? :assert_redirected_to $hash ...)
+          }
+        PATTERN
+
+        def_node_matcher :status_hash_value, <<~PATTERN
+          (hash <(pair (sym :status) $_) ...>)
+        PATTERN
+
+        def on_send(node)
+          status_method_call(node) do |status_node|
+            if status_node.hash_type?
+              # Handle hash arguments like { status: :unprocessable_entity }
+              status_hash_value(status_node) do |status_value|
+                find_deprecated_status_names(status_value)
+              end
+            else
+              # Handle positional arguments like head :unprocessable_entity
+              find_deprecated_status_names(status_node)
+            end
+          end
+        end
+
+        private
+
+        def find_deprecated_status_names(node)
+          if node.sym_type? && DEPRECATED_STATUSES.key?(node.value)
+            deprecated_status = node.value
+            preferred_status = DEPRECATED_STATUSES[deprecated_status]
+
+            message = format(MSG, deprecated: deprecated_status, preferred: preferred_status)
+
+            add_offense(node, message: message) do |corrector|
+              corrector.replace(node, ":#{preferred_status}")
+            end
+          elsif node.respond_to?(:children)
+            # Recursively search child nodes (handles ternary expressions, etc.)
+            node.children.each do |child|
+              find_deprecated_status_names(child) if child.is_a?(Parser::AST::Node)
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/rubocop/cop/rails_cops.rb b/lib/rubocop/cop/rails_cops.rb
index a8c7202dac..22b106b185 100644
--- a/lib/rubocop/cop/rails_cops.rb
+++ b/lib/rubocop/cop/rails_cops.rb
@@ -41,6 +41,7 @@
 require_relative 'rails/delegate'
 require_relative 'rails/delegate_allow_blank'
 require_relative 'rails/deprecated_active_model_errors_methods'
+require_relative 'rails/deprecated_http_status_names'
 require_relative 'rails/dot_separated_keys'
 require_relative 'rails/duplicate_association'
 require_relative 'rails/duplicate_scope'
diff --git a/spec/rubocop/cop/rails/deprecated_http_status_names_spec.rb b/spec/rubocop/cop/rails/deprecated_http_status_names_spec.rb
new file mode 100644
index 0000000000..c67d260437
--- /dev/null
+++ b/spec/rubocop/cop/rails/deprecated_http_status_names_spec.rb
@@ -0,0 +1,194 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::Rails::DeprecatedHttpStatusNames, :config do
+  context 'when Rack is older than 3.1' do
+    let(:gem_versions) { { 'rack' => '3.0.0' } }
+
+    it 'does nothing' do
+      expect_no_offenses(<<~RUBY)
+        render json: { error: 'Invalid data' }, status: :unprocessable_entity
+        head :payload_too_large
+      RUBY
+    end
+  end
+
+  context 'when Rack is 3.1 or later' do
+    let(:gem_versions) { { 'rack' => '3.1.0' } }
+
+    context 'with :unprocessable_entity' do
+      it 'registers an offense when using :unprocessable_entity in render' do
+        expect_offense(<<~RUBY)
+          render json: { error: 'Invalid data' }, status: :unprocessable_entity
+                                                          ^^^^^^^^^^^^^^^^^^^^^ Use `:unprocessable_content` instead of `:unprocessable_entity`. The `:unprocessable_entity` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          render json: { error: 'Invalid data' }, status: :unprocessable_content
+        RUBY
+      end
+
+      it 'registers an offense when using :unprocessable_entity in head' do
+        expect_offense(<<~RUBY)
+          head :unprocessable_entity
+               ^^^^^^^^^^^^^^^^^^^^^ Use `:unprocessable_content` instead of `:unprocessable_entity`. The `:unprocessable_entity` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          head :unprocessable_content
+        RUBY
+      end
+
+      it 'registers an offense when using :unprocessable_entity in redirect_to' do
+        expect_offense(<<~RUBY)
+          redirect_to some_path, status: :unprocessable_entity
+                                         ^^^^^^^^^^^^^^^^^^^^^ Use `:unprocessable_content` instead of `:unprocessable_entity`. The `:unprocessable_entity` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          redirect_to some_path, status: :unprocessable_content
+        RUBY
+      end
+
+      it 'registers an offense when using :unprocessable_entity in assert_response' do
+        expect_offense(<<~RUBY)
+          assert_response :unprocessable_entity
+                          ^^^^^^^^^^^^^^^^^^^^^ Use `:unprocessable_content` instead of `:unprocessable_entity`. The `:unprocessable_entity` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          assert_response :unprocessable_content
+        RUBY
+      end
+
+      it 'registers an offense when using :unprocessable_entity in assert_redirected_to' do
+        expect_offense(<<~RUBY)
+          assert_redirected_to some_path, status: :unprocessable_entity
+                                                  ^^^^^^^^^^^^^^^^^^^^^ Use `:unprocessable_content` instead of `:unprocessable_entity`. The `:unprocessable_entity` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          assert_redirected_to some_path, status: :unprocessable_content
+        RUBY
+      end
+
+      it 'registers an offense when using :unprocessable_entity in ternary expression' do
+        expect_offense(<<~RUBY)
+          render json: { error: 'Invalid data' }, status: some_condition ? :unprocessable_entity : :ok
+                                                                           ^^^^^^^^^^^^^^^^^^^^^ Use `:unprocessable_content` instead of `:unprocessable_entity`. The `:unprocessable_entity` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          render json: { error: 'Invalid data' }, status: some_condition ? :unprocessable_content : :ok
+        RUBY
+      end
+
+      it 'does not register an offense when using :unprocessable_content' do
+        expect_no_offenses(<<~RUBY)
+          render json: { error: 'Invalid data' }, status: :unprocessable_content
+        RUBY
+      end
+
+      it 'does not register an offense when using :unprocessable_entity in hash key' do
+        expect_no_offenses(<<~RUBY)
+          { unprocessable_entity: 'Invalid data' }
+        RUBY
+      end
+    end
+
+    context 'with :payload_too_large' do
+      it 'registers an offense when using :payload_too_large in render' do
+        expect_offense(<<~RUBY)
+          render json: { error: 'File too big' }, status: :payload_too_large
+                                                          ^^^^^^^^^^^^^^^^^^ Use `:content_too_large` instead of `:payload_too_large`. The `:payload_too_large` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          render json: { error: 'File too big' }, status: :content_too_large
+        RUBY
+      end
+
+      it 'registers an offense when using :payload_too_large in head' do
+        expect_offense(<<~RUBY)
+          head :payload_too_large
+               ^^^^^^^^^^^^^^^^^^ Use `:content_too_large` instead of `:payload_too_large`. The `:payload_too_large` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          head :content_too_large
+        RUBY
+      end
+
+      it 'registers an offense when using :payload_too_large in redirect_to' do
+        expect_offense(<<~RUBY)
+          redirect_to some_path, status: :payload_too_large
+                                         ^^^^^^^^^^^^^^^^^^ Use `:content_too_large` instead of `:payload_too_large`. The `:payload_too_large` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          redirect_to some_path, status: :content_too_large
+        RUBY
+      end
+
+      it 'registers an offense when using :payload_too_large in assert_response' do
+        expect_offense(<<~RUBY)
+          assert_response :payload_too_large
+                          ^^^^^^^^^^^^^^^^^^ Use `:content_too_large` instead of `:payload_too_large`. The `:payload_too_large` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          assert_response :content_too_large
+        RUBY
+      end
+
+      it 'registers an offense when using :payload_too_large in assert_redirected_to' do
+        expect_offense(<<~RUBY)
+          assert_redirected_to some_path, status: :payload_too_large
+                                                  ^^^^^^^^^^^^^^^^^^ Use `:content_too_large` instead of `:payload_too_large`. The `:payload_too_large` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          assert_redirected_to some_path, status: :content_too_large
+        RUBY
+      end
+
+      it 'registers an offense when using :payload_too_large in ternary expression' do
+        expect_offense(<<~RUBY)
+          render json: { error: 'File too big' }, status: some_condition ? :payload_too_large : :ok
+                                                                           ^^^^^^^^^^^^^^^^^^ Use `:content_too_large` instead of `:payload_too_large`. The `:payload_too_large` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          render json: { error: 'File too big' }, status: some_condition ? :content_too_large : :ok
+        RUBY
+      end
+
+      it 'does not register an offense when using :content_too_large' do
+        expect_no_offenses(<<~RUBY)
+          render json: { error: 'File too big' }, status: :content_too_large
+        RUBY
+      end
+
+      it 'does not register an offense when using :payload_too_large in hash key' do
+        expect_no_offenses(<<~RUBY)
+          { payload_too_large: 'File too big' }
+        RUBY
+      end
+    end
+
+    context 'with mixed deprecated statuses' do
+      it 'handles multiple deprecated statuses in the same code' do
+        expect_offense(<<~RUBY)
+          head :unprocessable_entity
+               ^^^^^^^^^^^^^^^^^^^^^ Use `:unprocessable_content` instead of `:unprocessable_entity`. The `:unprocessable_entity` status is deprecated.
+          head :payload_too_large
+               ^^^^^^^^^^^^^^^^^^ Use `:content_too_large` instead of `:payload_too_large`. The `:payload_too_large` status is deprecated.
+        RUBY
+
+        expect_correction(<<~RUBY)
+          head :unprocessable_content
+          head :content_too_large
+        RUBY
+      end
+    end
+  end
+end