The 21-year-old was released by Ipswich at the end of last season, but last week agreed a two-year deal, with an option for a third year, with the Seasiders.
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: "The things he (Holloway) had to say about the club and the way he wants to take the club forward really impressed me.
"I came up on Thursday night with my family so I haven't seen too much of the place, but the people I have met so far have made us all feel really welcome and I think it is a really good club to be part of.
"Hopefully we will get off to a good start both in pre-season and when the season starts."