Madonna is set to end her Celebration Tour with a free concert in Brazil.

On Monday, the Queen of Pop announced that she will perform a free show on Copacabana Beach in Rio de Janeiro, Brazil, on 4 May to mark the end of her world tour.

According to a press release, the show "will be free of charge as a thank you to her fans for celebration more than four decades of her music over the course of the epic global run of the tour."

The show will to take place in front of the Belmond Copacabana Palace Hotel. No tickets are required and admission will be on a first-come, first-served basis.

The event, which according to her official website will be her "biggest show yet," will be broadcast live on TV Globo.

Madonna, 65, is nearing the end of the last leg of her tour. Before heading to Brazil, she will perform in Texas, Georgia, Florida and Mexico.

The Like a Prayer hitmaker kicked off the Celebration Tour, which celebrates her four-decade career, in London in October. The tour was delayed by several months after she was hospitalised with a serious bacterial infection in June last year.

The announcement comes weeks after Madonna admitted the tour has been "emotionally" hard on her.

"This show every night is not really so hard on me physically. It's hard on me emotionally because I'm really telling you the story of my life. My heart is on my sleeve," the Material Girl singer told the crowd at a recent show at the Kia Forum in Los Angeles. "I've fallen off a lot of horses and broken a lot of bones...but nothing can stop me."