Tottenham have reached an agreement with Al-Duhail which sees defender Toby Alderweireld join the Qatari club.
The Belgian, 32, who joined Spurs in 2015, flew to Doha for discussions over the move last week.
He made 236 appearances for Spurs after joining from Atletico Madrid.
Alderweireld's contract ran to 2023, but the club's new technical director Fabio Paratici, together with manager Nuno Espirito Santo, is in the process of reshaping the squad.
The centre-back, who has won 113 caps for his country, formed a strong defensive partnership with compatriot Jan Vertonghen - now at Benfica - to help Spurs reach the Champions League final in 2019, which they lost to Liverpool.