The 37-year-old had been a free agent after he was released by Burnley following their relegation from the Premier League.
This deal comes as Guglielmo Vicario is set to leave the club this summer, with Italian giants Juventus and Napoli ready to fight for his signature.
Dubravka made 35 Premier League appearances for the Clarets as they fell back down the Championship. Despite the relegation, Spurs were keen to snap him up and announced his arrival on Wednesday afternoon.
The shot stopper spoke to the club website about the move which will see him work under manager Roberto De Zerbi.
"It's an exciting time for me, a new journey and new experience for me and my family. I'm looking forward to it.
"Everything moved pretty quickly and I'm really happy to be here. I've loved watching Roberto's teams over the years and know all about his style, vision and the fantastic fans here.
"Tottenham Hotspur is one of the biggest clubs in the Premier League and I can't wait to meet everyone and get started."
The move will provide competition and cover for Antonin Kinsky, who impressed between the sticks after Vicario suffered an injury in the second half of last season.