Clarke has made just four appearances for Tottenham since joining the club from Leeds United in 2019 and has had loan spells at Queens Park Rangers and Stoke City previously.
The winger has not featured for Tottenham this season and the club have been looking to loan him out since last summer.
Several clubs in the Championship are believed to have been interested in signing the former Leeds winger but he is on his way to League One in the latter half of the season.
It has been claimed Sunderland are putting him through a medical at the moment ahead of signing him on loan.
A deal is in place between Sunderland and Tottenham for Clarke to spend the rest of the campaign at the Stadium of Light.
He will sign a loan contract with the Black Cats once the club receive the all-clear from their medical team.
Sunderland are second in League One and Lee Johnson will hope that Clarke will aid his side’s attempts to get automatic promotion to the Championship this season.