The 32-year-old has struggled to make an impact at the KC Stadium this season due to a series of knee injuries that have restricted him to just nine first-team appearances.
Bullard, who has struggled to win back a regular place in the starting line-up under manager Nigel Pearson since regaining full fitness, will team back up with boss Paul Jewell at Portman Road.
Jewell was in charge at Wigan when they paid £275,000 to Peterborough for Bullard in January 2003.
Source: PA
Source: PA