Evans, brother of Max, a cousin of Radio 2 DJ Chris Evans, and a former boyfriend of Kelly Brook, quit the game aged 24 after suffering a serious neck injury during a game in 2010.
He said: "I'm so happy to be doing the show, I cannot wait to get started. I'm really looking forward to my Strictly makeover - bring on Strictly and bring on the spandex."
Evans, who played 10 times for Scotland and had stints with London Wasps and Glasgow Warriors before his career ended, is the fourth celebrity contestant announced for the new series joining This Morning presenter Alison Hammond, Judy Murray and The Saturdays singer Frankie Bridge in the hit BBC ballroom show.
They will be joined by 11 other celebrities competing for the glitter ball trophy when the show returns to BBC1 this autumn.
The new series will be the first one without veteran host Sir Bruce Forsyth, with Tess Daly and Claudia Winkleman sharing the presenting job.