We reached agreement with the Bundesliga club for the versatile midfielder's immediate transfer after he'd initially agreed terms to join us this coming summer.
Capped three times by Germany, Lewis, who will wear number 23, took part in his first training session on Tuesday and is straight into the squad to face Norwich City at Carrow Road in the Premier League on Wednesday night.
In joining us now, he will miss out on Schalke's continuing Champions League campaign - underlining his commitment to Spurs.
"Ever since I decided to join Spurs in the summer, I had the feeling that I wanted to come here straight away," said Lewis, who scored four times in 27 appearances for Schalke this season and played in all six of the club's Champions League fixtures.
"The talks with Andre Villas-Boas also made me feel so comfortable and I wanted to come here as soon as possible.
"All respect to Schalke as well. I had some great times there. I’m thankful to them. They gave me the opportunity to produce at the higher level and to get an offer from a team like Tottenham. I thank them for that."
Lewis was welcomed by Andre and the squad in typical style on Tuesday as they formed a tunnel (like a guard of honour) that he had to run through as an initiation before training!
"I had to go through the tunnel for the new players and I got a little stick, so it all started with a smile," he said. "I’ve had a fantastic first day and I can’t wait to play my first game.
"It’s fantastic to be here, a huge club, a club that’s getting bigger and bigger every year.
"There is so much quality here, the coaching staff is fantastic, the facilities - it’s the full package. Like footballer’s say, I’m over the moon!
"I can now settle in to the Tottenham Hotspur way for a few days before the international fixtures next week."
It's also fair to say that Lewis has been blown away by the facilities at our new Training Centre.
"It’s massive, fantastic. The best I’ve seen. I’m so proud to be here and to be able to work in such a fantastic facility. It’s Champions League (the facilities) and it’s now up to us to get there."