A long-running transfer saga has come to an end after the former Ajax captain was pictured with Spurs boss Andre Villas-Boas and new acquisition Gylfi Sigurdsson
The Belgium international's move had been confirmed by both sides on Sunday but all the paperwork is now complete and he becomes Spurs' second acquisition of the summer.
Vertonghen had been linked with a move to White Hart Lane for a number of months but the move reportedly hit a snag over the defender's demands for a cut of the transfer fee.
The 25-year-old made 31 appearances as Ajax captain last season, scoring eight goals from the back as the Amsterdam club clinched the Eredivisie title.
Vertonghen is Andre Villas-Boas' second signing since his appointment at the north London club, following the capture of Gylfi Sigurdsson from Hoffenheim.