diff --git a/changelog/fix_incorrect_autocorrection_of_rails_action_order.md b/changelog/fix_incorrect_autocorrection_of_rails_action_order.md
new file mode 100644
index 0000000000..f591bf2b95
--- /dev/null
+++ b/changelog/fix_incorrect_autocorrection_of_rails_action_order.md
@@ -0,0 +1 @@
+* [#837](https://github.com/rubocop/rubocop-rails/pull/837): Fix incorrect autocorrection of `Rails/ActionOrder` about comments. ([@r7kamura][])
diff --git a/lib/rubocop/cop/rails/action_order.rb b/lib/rubocop/cop/rails/action_order.rb
index 45487ad492..2cb0a64aa4 100644
--- a/lib/rubocop/cop/rails/action_order.rb
+++ b/lib/rubocop/cop/rails/action_order.rb
@@ -35,6 +35,7 @@ class ActionOrder < Base
         extend AutoCorrector
         include VisibilityHelp
         include DefNode
+        include RangeHelp
 
         MSG = 'Action `%<current>s` should appear before `%<previous>s`.'
 
@@ -80,7 +81,30 @@ def register_offense(previous, current)
         end
 
         def correction_target(def_node)
-          def_node.each_ancestor(:if).first || def_node
+          range_with_comments_and_lines(def_node.each_ancestor(:if).first || def_node)
+        end
+
+        def add_range(range1, range2)
+          range1.with(
+            begin_pos: [range1.begin_pos, range2.begin_pos].min,
+            end_pos: [range1.end_pos, range2.end_pos].max
+          )
+        end
+
+        def range_with_comments(node)
+          ranges = [
+            node,
+            *processed_source.ast_with_comments[node]
+          ].map do |element|
+            element.location.expression
+          end
+          ranges.reduce do |result, range|
+            add_range(result, range)
+          end
+        end
+
+        def range_with_comments_and_lines(node)
+          range_by_whole_lines(range_with_comments(node), include_final_newline: true)
         end
       end
     end
diff --git a/spec/rubocop/cop/rails/action_order_spec.rb b/spec/rubocop/cop/rails/action_order_spec.rb
index 0e7fae8c09..6197e32c94 100644
--- a/spec/rubocop/cop/rails/action_order_spec.rb
+++ b/spec/rubocop/cop/rails/action_order_spec.rb
@@ -187,4 +187,29 @@ def index; end
       RUBY
     end
   end
+
+  context 'when action has some comments' do
+    it 'corrects comments properly' do
+      expect_offense(<<~RUBY)
+        class UserController < ApplicationController
+          # show
+          def show; end
+
+          # index
+          def index; end
+          ^^^^^^^^^^^^^^ Action `index` should appear before `show`.
+        end
+      RUBY
+
+      expect_correction(<<~RUBY)
+        class UserController < ApplicationController
+          # index
+          def index; end
+
+          # show
+          def show; end
+        end
+      RUBY
+    end
+  end
 end