Auto-import

When you reference a symbol that has not yet been imported, CLion helps you locate the file – which is typically a header that contains the declaration or definition of that symbol – and adds it to the list of includes.

Import a missing header file

Type a reference to a non-imported class or function.
Press Alt+Enter. The import symbol will be added to the imports section:
If there are multiple choices for auto import, you will see the corresponding popup:
Press Alt+Enter and select the preferred option from the list:
If the auto-import popup is disabled in Settings | Languages & Frameworks | C/C++ | General, you will see a quick-fix when hovering over a non-imported symbol:
If there are multiple choices for auto import, click More actions... and select the preferred option from the list:

Configure auto-import

There are several settings that control the behavior of the auto-import feature.

Enable or disable popups for import actions in Settings | Languages & Frameworks | C/C++ | General:
You can use auto-importing during code completion, which automatically adds include directives after completing a symbol. Configure this option in Settings | Editor | General | Code Completion:
Select the preferred behavior for importing items from the drop-down list:
Below, you can also enable or disable the option Add #include after completion of member of incomplete class.

There are also two syntax-related options in Settings | Editor | Code Style | C++ | Syntax Style:

Option	Functionality
Sort include directives	Highlights `#include` directives that violate the sorting order.
Use angle brackets instead of quotes	Allows you to specify cases where generated include directives are added in angle brackets.

12 February 2026