Keane left Spurs for Anfield for £18million last summer, but has failed to settle at Liverpool.
A statement on Tottenham’s official website read: “We are delighted to announce that we have reached agreement for the transfer of Robbie Keane back to the club from Liverpool.”
“It was a difficult decision to make to leave Tottenham in the summer,” Keane said. “It proved not to be the right move for me.
“I know some Spurs fans will feel I let them down by leaving but I can assure them I shall be giving my all for this club – this club has terrific fans and I want to repay them for all their support. We’ve got to get on and fight our way up that league table.”