The announcement ends months of speculation over his future with the North London side, with Barcelona, Chelsea, Manchester United and Bayern Munich all thought to have been monitoring his contract situation.
The 23-year-old still had four seasons remaining on his existing deal with Mauricio Pochettino's side but had been seeking a two-fold interest on his salary of £60,000 a week.
"It's amazing. Everyone knows how much I love this team and what I feel for this club," said Kane of the deal.
"To sign another contract is a special feeling. We've got a great young squad and the club is moving in the right direction."
Kane has been with Spurs since the age of 11 and has been a staple of the first team for the last three seasons, scoring 54 goals in 91 Premier League appearances.