The Kings announced the deals Thursday. Terms of the contracts were not released.
Sacramento selected Casspi 23rd overall in the 2009 draft. He was the first Israeli-born player to be drafted by an NBA team and play in the league.
Casspi has averaged 7.7 points, 3.8 rebounds and 20.7 minutes in his career with Sacramento, Cleveland and Houston. He averaged 6.9 points and 3.7 rebounds in 71 games with the Rockets last season.
Hollins has averaged 3.8 points, 2.2 rebounds in his eight-year career. He has played for Charlotte, Dallas, Minnesota, Cleveland, Boston and the Los Angeles Clippers.