Chris Liddle, Steffan Piolet and Ashar Zaidi have left Sussex following the end of the season.
Left-arm-seamer Liddle, 31, had been at Hove since 2006 and was a regular in one-day cricket.
Zaidi, 34, made seven appearances in the County Championship this summer, scoring 354 runs and taking 11 wickets.
Fellow all-rounder Piolet, 27, played five times in white-ball cricket but has now retired from cricket to pursue a career in recruitment.
"It is always a sad time when we release any player," Sussex cricket manager Mark Robinson said.
"Lids has been with us for nine years and enjoyed much success, Ash proved to have a shrewd cricket brain and Steff was a fierce competitor."