Defender Terence Kongolo and midfielder Tyrese Francois are also leaving Craven Cottage.
The contracts of all four players expire this summer.
The club are in talks with Willian and Bobby De Cordova-Reid, whose contracts are also about to expire, while youngsters Harvey Araujo and George Wickens have been offered new deals.
Centre-back Tosin, 26, rejected offers of a new contract and is set to join Chelsea.
He joined Fulham from Manchester City in 2020 and made 119 league appearances for the Whites.
