Spurs said in a statement they had reached agreement for the transfer, put at around 17 million pounds by local media, after Paulinho successfully completed a medical examination.
The 24-year-old, who scored 34 goals in 167 games for Sao Paulo-based Corinthians, shone in Brazil's winning Confederations Cup campaign last month.
"I want to thank Tottenham for believing in me," he told the club website.
"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.
"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," added the player after a visit to the club's training centre.
Paulinho has been capped by Brazil 17 times and was a key part of the Corinthians side that beat Chelsea in the Club World Cup final last December.
He joins Brazilian international midfielder Sandro at the North London club.
Tottenham, managed by Portuguese Andre Villas-Boas, finished fifth last season despite a club-record points total and missed out on a Champions League place. They will play in the Europa League instead.
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