The 28-year-old spent last season on loan with Spurs after being told that he was surplus to requirements at Manchester City.
Adebayor returned to City this summer as both clubs struggled to reach an agreement over a fee for the Togo international.
However, Spurs confirmed this afternoon that they have now found some common ground with the Premier League champions, who have agreed to let Adebayor leave following a three-year stint on their books.
"I am pleased to be signing for Spurs on a permanent basis after finally agreeing my departure with Manchester City," he told the club's official website.
"It may have taken longer than expected but I am delighted to be back at Tottenham Hotspur. I really enjoyed my time here last season and I am hoping we can achieve great things together again."
Adebayor is expected to start against West Bromwich Albion on Saturday afternoon.