The men's 100m breaststroke SB12 event at the 2012 Summer Paralympics took place at the London Aquatics Centre on 8 September.

There were two heats; the swimmers with the seven fastest times advanced to the final, while because of tied times in the heats the eighth final place was decided by a swim-off.

Qualification swim-off at 12.11.

WR = World Record.

Official London 2012 Paralympics Results: Heats Archived 2012-09-13 at the Wayback Machine Official London 2012 Paralympics Results: Final Archived 2012-09-13 at the Wayback Machine