The 21-year-old was released by the Tractor Boys at the end of last season, but has agreed a two-year deal, with an option for a third year, with Ian Holloway's men.
He had fallen out of favour at Portman Road and last term spent time on loan at Darlington, Northampton and Brentford.
Clarke told Blackpool's official website: "I had a good time at Ipswich but a new manager came in and these things happen.
"However, it is not about the past. I am here now and I can't wait to meet the rest of the lads and get started."