Heskey began training with the club earlier this month alongside former Chelsea and Barcelona star Eidur Gudjohnsen.
Gudjohnsen securing a return to his former employers by putting pen to paper after manager Neil Lennon was impressed with what he had seen.
Lennon, who played with Heskey at Leicester City, took a little longer to decide on the future of the 36-year-old, but it was revealed on Wednesday the striker had been given a contract.
"Bolton Wanderers have completed the signing of Emile Heskey on a short-term deal," a statement read.
"The former England international, aged 36, has impressed during a recent trial period with the club.
"And Neil Lennon has now moved to sign free agent Heskey, who was most recently on the books of Australian A-League side Newcastle Jets.
"Prior to his spell in New South Wales, Heskey turned out for Leicester, Liverpool, Birmingham, Wigan and Aston Villa and represented England a total of 62 times.
"Bolton Wanderers now require international clearance in order for Heskey to be available to feature in the Boxing Day game against Blackburn."
