An edit-a-thon (sometimes written editathon) is an organized event where editors of online communities such as , OpenStreetMap, and edit and improve a specific topic or type of content, typically including basic editing training for new editors. They often involve meetups, but can be distributed as well. The word is a portmanteau of "edit" and "marathon".
The OpenStreetMap community has also hosted a number of edit-a-thons.