Forwards Kyle Lafferty and Greg Kiltie, defender Kirk Broadfoot and midfielder Mitch Pinnock have left Kilmarnock after their relegation.
The Ayrshire club said that Lafferty, Kiltie and Pinnock had "decided to move on" from Rugby Park as the club drops to the Scottish Championship.
"Kirk Broadfoot's time with the club will also come to an end," they said.
But discussions continue with veteran winger Chris Burke and defender Calum Waters "is set to sign fresh terms".
Manager Tommy Wright has already started rebuilding his squad and has made five signings in the past three days.
Centre-half Euan Murray arrived after leaving Dunfermline Athletic, fellow defender Jack Sanders from Wigan Athletic, midfielders Daniel Armstrong and Blair Alston from Raith Rovers and Falkirk respectively, while striker Scott Robinson drops down from the Premiership after exiting Livingston.
Northern Ireland striker Lafferty finished the season as Kilmarnock's top scorer, with 13 goals in 13 games, despite the 33-year-old only signing in February.
Fellow former Rangers player Broadfoot made 45 appearances after the 36-year-old returned for a second spell at Rugby Park from St Mirren in January 2020.
The 24-year-old Kiltie is a product of Kilmarnock's youth academy and scored seven times in 33 appearances last season.
Pinnock, the 26-year-old who signed after leaving AFC Wimbledon last summer, scored five times in 37 appearances.
Meanwhile, two 19-year-olds - midfielder Tomas Brindley and striker Kyle Connell - and 21-year-old goalkeeper Curtis Lyle continue discussions with the club over new contracts.