The Argentina striker will return to parent club Juventus after his six-month-long loan, while Gary Cahill and Rob Green also leave the club.
Keeper Eduardo and youngster Kyle Scott have also been let go as the Blues prepare their squad - and new manager - for next season.
Higuain, 31, flopped at Stamford Bridge with just five goals in 18 games.
The Blues have decided not to pursue another loan move or permanent deal despite being hamstrung by a transfer ban this summer.
Higuain, who reportedly earned an eye-watering £270k-a-week at Chelsea, will instead return to Juve where he will link up with Maurizio Sarri, who brought him to the Premier League.
At least he returns £6.2m better off.
Cahill, 33, has officially left after seven years at Stamford Bridge.