Mark Kerr will sign for Dunfermline on Friday until the end of the season.
The 29-year-old midfielder, who has played for Falkirk, Dundee United and Aberdeen, left the Dons to sign for Greek club Asteras Tripolis in 2010.
Manager Jim McIntyre told the Pars website: "We are signing a player of real quality who will give us real energy in the middle of the park.
"He is a box-to-box midfielder, he can play the holding role or an attacking midfielder role. He gives us options."
The former Aberdeen captain had been on trial at Rugby Park, though Kilmarnock manager Kenny Shiels had stressed that his signing priority during January was to find a striker.
Kerr spent five years with Falkirk and had a similar spell with Dundee United before spending two years at Pittodrie.
But he moved at the end of his contract to the Greek Superleague club, who finished 13th last season, and last played for the Tripoli-based outfit in September.
Shiels, meanwhile, is continuing his search for additional forward cover having all but given up hope of signing trialist Derek Riordan.
The former Hibernian and Celtic forward has been looking for a new club since November after an ill-fated five-month spell in China with Shaanxi Chan-Ba.
"We need a striker to support Paul Heffernan and that would give us a great fillip if we could get one in before the end, but they're an expensive commodity," he said of his chances of adding a striker before the January transfer window closes.