The Wales superstar is back to the Premier League after plying his trade in La Liga for seven years.
Bale left north London in the summer 2013 to join Real Madrid for a then world-record transfer fee of £85m.
The former Southampton man established himself as one of the best players in Real Madrid during his early seasons at the Santiago Bernabeu. He won every possible laurel in Madrid which includes two league titles and four Champions League trophies.
The 31-year-old completed his medical on Friday in Madrid before joining Spurs in a move that will cost the English side around £20m in wages and loan fees.
Bale was accompanied by team-mate Sergio Reguilon, who also finalized a move to Tottenham on a five-year deal.
"It's nice to be back. It's such a special club for me where I made my name, what an amazing club with amazing fans, it's incredible to be back," Bale told the club's website.
"Hopefully now I can get some match fitness, get underway and really help the team to win trophies.
"I always thought when I did leave that I would love to come back one day, the opportunity has now arisen and I feel like it is a good fit at a good time.
"I am hungry and motivated to do well for the team. I can't wait to get started.
"By going to Madrid and winning trophies, and going far with the Wales national team, I have got that winning mentality.
"You don't realise until you are there in finals and those situations. Hopefully I can bring belief into everybody that we can win trophies. The target is to do that this season, I want to bring that mentality back to Tottenham.
"Since I have left the club has been building, the stadium is incredible, the training ground is better than before. It's an exciting time."
