The 79-year-old, who plays Ken Barlow in the ITV soap, exposed the fraud after the likes of Christine Bleakley, Adrian Chiles, John Terry and Roache's own girlfriend Emma Jesson were targeted.
"I really do want people to know that the Bill Roache account on Twitter is run by an imposter and most definitely not me," he told the Daily Star. "I am not on Twitter and never have been. I would not know how to Tweet to save my life!
"I am not even on Facebook, despite there being three accounts in my name on there as well."
The fake account was created in 2009, has over 6,500 followers and is listed under Twitter's "top people".
"It baffles me why someone would want to pretend to be someone they are not and to say some quite outrageous things about people I know," he said. "I hope this imposter is stopped as soon as possible."
Roache said last year that he wants to "keep appearing on Coronation Street for the rest of [his] life."