This feature is only available in the new Insightly.
To delete a page layout:
- Go to System Settings > Objects and Fields.
- Click the object that contains the layout you want to delete.
- From the Object Management list, select Page Layouts.
- Click the three dots on the right and select Delete This Layout.
- Select a replacement layout from the dropdown. This will update the records that used the old layout with the layout you select.
- Click Delete Page Layout.
- You will see a message confirming that the page layout has been deleted.