The 33-year old, who spent the end of last season on loan at Swindon from Wolves, becomes Coventry’s second summer signing.
Coventry boss Tony Mowbray told the club’s official website: “Since I joined the club last season, I’ve spoke about the importance of leadership and experience in the dressing room.
“Sam has a wealth of experience at Premier League and Championship level but also captained Wolves to the League One title where he was ever-present.
“He knows what it takes to get out of this division and can play across the back-line as well as in midfield.
“I’m delighted to see him sign up and I see him as a crucial member of our squad going into the 2015/16 season.”
Ricketts started out at Oxford and had spells at Telford and Swansea before Hull paid £300,000 for him in July 2006.
He also gained Premier League experience at Bolton, who he signed for in July 2009, and moved on to Wolves last summer.