The north Londoners have long been confident of bringing last season's loanee permanently, as Goal.com exclusively revealed in July, despite returning to training with City in the meantime.
Negotiations had stalled in early August when Adebayor threatened to pull the plug unless he was handed the transfer free directly. Goal.com later explained that Roberto Mancini's side have agreed to subsidise his wages as the deal looked to be heading down to the wire.
The 28-year-old striker, who had spent time on loan at Real Madrid before his Spurs spell in 2011-12, also broke the news in a celebratory tweet, promising fans that he is hungry to score more goals for the club.
"We are delighted to announce that we have completed the transfer of Emmanuel Adebayor from Manchester City. More to come soon!" Tottenham announced on their official Twitter account.
The striker himself added: "I'm back!!!! Tottenham here I come!! I'm hungry for goals...Get ready."
After scoring 18 goals in 37 appearances for the Lilywhites last season, new boss Andre Villas-Boas was eager to add the forward to his side, with Jermain Defoe the only recognised senior striker in the squad when he took charge.
In an interview on Tottenham's official website, Adebayor spoke of his happiness to be signing with the last year's fourth-placed Premier League team, expressing his ambition to excel there.
"I am pleased to be signing for Spurs on a permanent basis after finally agreeing my departure with Manchester City," he declared.
"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."