The 36-year-old, who has been without a club after leaving Australian A-League side Newcastle Jets, has been training with Neil Lennon's men and played for their under-21 side this week.
Heskey has done enough to impress Lennon, who he played with at Leicester, and earned a short-term deal, following in the footsteps of fellow veteran striker Eidur Gudjohnsen who signed a similar contract earlier this month.
Wanderers must wait for international clearance in order for Heskey, whose last English club was Aston Villa, to be available for their Boxing Day clash with Blackburn.
Heskey has played 62 times for England and also featured for Liverpool, Birmingham and Wigan.
Source : PA
Source: PA