The 35-year-old singer is said to have filed papers at the High Court on 25 September, ahead of the boyband's UK comeback tour.
Bandmate Duncan James also filed for bankruptcy in September under his real name Duncan Inglis.
Earlier this year, Simon, Duncan, Antony Costa and fourth member Lee Ryan, took part in ITV's The Big Reunion which saw groups including B*Witched, 5ive and Liberty X attempt to relaunch their music career.
Blue, who are touring in the UK this month, released their fourth studio album Roulette earlier this year.
In December, the boys are set to support pop legends Wet Wet Wet on their UK arena tour, and are currently joining their fellow Big Reunion stars to record a Christmas charity single.
Father-of-one Simon, is yet to publicly comment. Reveal also contacted his rep, who said there is no comment to give at this time.
Watch Blue's video for 'Without You' below: