Reid has found opportunities hard to come by at the Stadium of Light and he will now hope Ian Holloway can revive his career in the north-west.
The 28-year-old Republic of Ireland international joined Sunderland from Charlton in January 2008 for £4m and he scored six goals for the club in 70 appearances.
He had a spell on loan at Sheffield United earlier this season and he scored twice in nine appearances.
The midfielder began his career at Nottingham Forest, making 160 appearances for the Reds.
He joined Spurs for £4m in January 2005 and later had a spell at Charlton before moving to Sunderland.