The goalkeeper has left Newcastle after seven-and-a-half years at the club, signing a one-year contract with the Clarets, and replacing James Trafford, who left for Manchester City.
Dubravka will wear the No.1 shirt at Turf Moor.
“I’m delighted to be here,” said Dúbravka.
“It’s a really exciting time to be joining this club, ahead of our return to the Premier League.
“I’ve only heard really positive things about the club, the culture and the environment we work in, so I’m excited about getting going with the season kicking off next weekend.”
“Burnley had a fantastic campaign last season, built on a superb defensive record, and I can’t wait to come in and add my experience and quality to what looks an exciting squad of players.
“I’m really looking forward to playing for the club in front of our passionate fans.”
Dubravka made 179 appearances for Newcastle after joining, initially on loan, in January 2018.
He played a key role in last season’s Carabao Cup triumph, making four appearances and keeping three clean sheets, including in each leg of the semi-final victory over Arsenal.
He also featured 10 times during the last Premier League campaign, keeping five clean sheets to help the club achieve UEFA Champions League qualification.
Newcastle said in a statement: “Everyone at the club would like to thank Martin for his efforts while with Newcastle United and wishes him well for the future.”
Odysseas Vlachodimos could also leave Newcastle this summer, with a loan move being lined up for the Greek goalkeeper.
Aaron Ramsdale joined from Southampton last week and compete with Nick Pope for the gloves.
