Michael Hector will join Fulham from London neighbours Chelsea in January after signing a contract until 2022.
The 27-year-old centre-back has already started training with Fulham - who have the option to extend his deal for a further 12 months - before officially completing his move in the New Year.
After arriving at Craven Cottage, Hector told Fulham's website: "It's good to now be a part of the setup here. Hopefully things can work out well and we can get promoted.
"I know how tough the Championship is and it won't be any different for us. We'll have to work hard for it but the squad is very good and my job will be to help them push for promotion."
Hector joined Chelsea from Reading in 2015 but never played a competitive game for the club.
He spent the majority of his time out on loan, and had spells at Reading, Frankfurt and Hull.
Hector, who has 30 caps for Jamaica, spent last season on loan at Sheffield Wednesday, where he won their player of the year award.