Allan, 32, was a free agent after leaving Arbroath at the end of last season and had been linked with ambitious Lowland League outfit East Kilbride.
Allan is fresh from picking up a Northern Ireland Premiership winners’ medal after spending the second half of the 2023/24 campaign on loan at Larne from the Lichties.
As well as adding experience and creativity to the Maroon Machine midfield, Allan will assist Michael Tidser’s coaching staff.
Having made nine appearances for United, Allan joined West Bromwich Albion after failing to agree a new contract with the Tannadice outfit. Loan stints with Portsmouth, MK Dons and Birmingham City followed.
Allan returned north of the border in 2014 and enjoyed a dazzling one-year spell with Hibernian, helping the capital club win the Scottish Championship and earning a move to Celtic.
However, that proved to be another ill-fated move and Allan was farmed out on loan to Rotherham, Dundee and Hibs, before making the return to Easter Road a permanent one.
Allan was diagnosed with the heart condition, hypertrophic cardiomyopathy, during his second stint with the Hibees and ultimately left the club in 2022 following a brief loan at Inverness.
He subsequently turned out for Arbroath and Larne.
