Aston Villa paid Belgian side Genk £10m for Samatta’s signature in the January transfer window and the Tanzania captain scored twice in 16 appearances for Dean Smith’s side. One of his two goals came in a 2-1 defeat against Manchester City in the Carabao Cup final.
Samatta’s loan move will be made permanent at the end of the season.
“Our club has added Mbwana Samatta, captain of the Tanzania national team from Aston Villa, England, to their squad for four years,” a statement from Fenerbahce read.
“This season, the player who will wear our shirt on loan will receive the testimonial at the end of the season. We welcome Samatta and wish him well in the striped jersey.”
Samatta’s place in the Aston Villa team came under threat once a club record £28m was paid to sign Ollie Watkins from Brentford and Burkina Faso striker Bertrand Traore was also brought in from Olympique Lyon earlier this week.
"I know how big a club Fenerbahce is," Samatta said after completing his move to Turkey.
"I am happy to be here in such a family because it will be a new and big challenge for me.
"Fenerbahce has a lot of supporters and they always want to win. I also want to win. I came with this request, I am very happy and I hope we will win many trophies."
Samatta could make his debut against Galatasaray this weekend.