The 25-year-old Sweden international picked up the injury in Spurs' 2-0 Premier League loss at home against Crystal Palace last weekend. Spurs did not provide a timeline on Kulusevski's return.
"We can confirm that Dejan Kulusevski suffered an injury to his right patella in our Premier League fixture against Crystal Palace last weekend," Spurs said in a statement.
"Following further specialist consultation, the midfielder has undergone surgery today and will commence his rehabilitation with our medical staff immediately."
Spurs have also lost midfielder James Maddison to a season-ending knee injury.
They can end a 17-year trophy drought when they take on Manchester United in the Europa League final on May 21 in the Spanish city of Bilbao.
17th in the Premier League with 38 points, they next take a trip to Aston Villa on Friday before hosting Brighton on May 25 for their final game of the season.