The 24-year-old, who has passed a medical, was a regular for Brazil during their Confederations Cup campaign which culminated in a 3-0 win over Spain on Sunday.
Neither the fee or length of contract has been disclosed by the club.
He told the club's official Twitter account, @SpursOfficial: "I am very happy and excited to have joined Spurs. It's a huge pleasure for my career to be at a club as big as Tottenham."
Paulinho has become Andre Villas-Boas' first summer recruit as he looks to reshape his squad ahead of a push for a top-four place in the Barclays Premier League next season.
The player revealed during the tournament in his native country that a bid from Spurs to seal his signature had been lodged and that north London was his most likely destination.
Inter Milan and Real Madrid were also believed to be interested in a move for the former Bragantino midfielder, who scored twice during the Confederations Cup, following on from his equalising goal in Brazil's 2-2 draw with England last month.
And the midfielder is hopeful of maintaining his form with his new club. "It's a huge pleasure for my career to be at a club as big as Tottenham. I know it will be a huge challenge but I think I can help all my colleagues to succeed and give a lot of happiness to the supporters," he said.
"The training centre is amazing and I'm very impressed about the conditions Tottenham offers to the players. I will focus on my job and use the facility as much as possible.
"We used to watch the Premier League in Brazil - including Tottenham - and this club has big players. I just want to help them to succeed here. It's nice to have another Brazilian in the squad and I'm excited to meet with Sandro and all the players."