Hughes goes straight into the squad for tomorrow's SPL home clash against Dunfermline after signing this morning.
The 29-year-old, who started his career with Rangers, was a free agent after spells with Leicester City, Motherwell (twice), MK Dons (on loan) and Norwich City.
Hughes made his Scotland debut in 2009, playing the last twenty minutes as a substitute against Japan in a friendly.
Dons boss Craig Brown has been looking to strengthen his midfield following the news that Kari Arnason rejected a new contract offer at Pittodrie, the departure of Jack Grimmer to Fulham and the continued absence of Yoann Folly due to a serious respiratory problem.