Dubravka joins on the expiry of his Burnley contract on July 1, having played 35 times in the Premier League last season as the Clarets were relegated. He has made 197 Premier League appearances in total across his career, recording 51 clean sheets, and spent eight years at Newcastle United before a loan spell at Manchester United in 2022-23.
The signing is De Zerbi's fourth of the summer, following the free-transfer arrivals of Argentine centre-back Marcos Senesi from Feyenoord and Scottish left-back Andy Robertson from Liverpool, as well as the £52m capture of Netherlands defender Jan Paul van Hecke from Brighton & Hove Albion.
"It's an exciting time for me, a new journey and new experience for me and my family," Dubravka said. "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."
De Zerbi was equally positive.
"I am very happy because Martin is a goalkeeper with big experience and a strong mentality. He has very important qualities for me and will bring balance, leadership and competitiveness to our dressing room."
Dubravka arrives into an unsettled goalkeeping situation at the Tottenham Hotspur Stadium. Guglielmo Vicario, who served as first choice for much of last season, is attracting interest from Serie A clubs and his departure is possible. Kinsky, 23, produced arguably his most important moment of the season with a crucial save against Leeds United that helped keep Spurs in the Premier League, having dramatically recovered from being substituted in the 17th minute of a Champions League tie at Atlético Madrid after conceding three goals.
A formal decision on who holds the number one position under De Zerbi will become clearer once Vicario's future is resolved.