The 29-year-old will be on the plane to Poland and Ukraine alongside fellow strikers Wayne Rooney, Danny Welbeck and Andy Carroll.
"I'm delighted because I knew last summer I had a massive season coming up and I worked hard on my fitness to be as sharp as possible," Defoe told Tottenham's official website. "I think that work has paid off.
"I thought the World Cup was a fantastic experience and to have the opportunity to represent England at another major tournament is amazing. I always remember watching the tournaments on TV, watching Euro '96, and to be part of it now is something special."
England's first group match will be against France on June 11.