The Belgium international, who is André Villas-Boas’ fourth summer signing, sealed his switch to White Hart Lane after passing a medical with the north Londoners.
“You can see over the last few years that Spurs have played well, everybody knows it’s a good team and a good club and that’s why I wanted to come here,” Dembélé told Tottenham’s website.
“The club has plans to do lots of good things and that’s why I want to be a part of it.”
Dembélé scored seven times in 74 appearances for Fulham after former Cottagers manager Roy Hodgson signed the forward from AZ Alkmaar in 2010.
The 25-year-old will now link up with compatriot Jan Vertonghen, who joined Tottenham from Eredivisie champions Ajax in July.
And Tottenham’s latest signing revealed the Belgian defender played a part in convincing him to move to White Hart Lane.
“I know Jan from when I was 10 years old, we played together then,” he added. “I know him well, he’s a great guy and he’s said a lot of good things about this club.
“He says there are friendly people here and for me, that’s very important, to feel great somewhere. I’m sure I will here.”
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