The surviving members of the chart-topping quartet announced his death in a Twitter post on Sunday.
In the online tribute, tenors David Miller, Sébastien Izambard and Urs Bühler remembered the baritone as a “beautiful soul.”
“It is with heavy hearts that we are letting you know that our friend and partner, Carlos Marin, has passed away,” the statement read.
“He will be missed by his friends, family and fans. There wiIl never be another voice or spirit like Carlos.”
“For 17 years the four of us have been on this incredible journey of Il Divo together, and we will miss our dear friend. We hope and pray that his beautiful soul will rest in peace.”
Marín who was vaccinated had been performing with the band in the UK in December before their tour was postponed “due to illness.”
The vocalist’s death comes days after the group confirmed on Twitter he had been hospitalized.
Marín, who was born in Germany but raised in Madrid, was one of the founding members of Il Divo — meaning “divine male performer” in Italian — which was created by Simon Cowell in 2003 under his SyCo record label.