Cardiff pair Aron Gunnarsson and Kadeem Harris will leave the club when their contracts expire at the end of the month.
Iceland midfielder Gunnarsson made 28 Premier League appearances this season and winger Harris featured in 13 games, mainly as a substitute.
"First-team players Aron Gunnarsson and Kadeem Harris, having been with Cardiff since July 2011 and January 2012 respectively, will depart south Wales this summer at the end of their current contracts," said Cardiff, who released their retained list on their official website.
Cardiff confirmed Stuart O'Keefe, who spent last season on loan at Plymouth, will also leave the club when his deal expires.
The Bluebirds said they were in talks with goalkeeper Brian Murphy and had made offers to nine members of their under-23s squad.
