A statement posted on Gibb's Web site and attributed to his family said he died "following his long battle with cancer and intestinal surgery," CNN reported.
Gibb had been hospitalized in London for colorectal cancer and pneumonia. and was in a coma before he awoke last month. His wife, Dwina Murphy-Gibb, told ITV News at the time the singer-songwriter was "really happy" and "just wants to get out" of The London Clinic and go home.
"They gave him an under 10 percent survival chance and he has beaten the odds," Gibb's son, Robin-John, said. "He really is something else."
With the death of Robin Gibb, Barry Gibb, 65, is the sole remaining member of the Bee Gees. Robin's twin brother, Maurice, died in 2003. A younger brother, singer Andy Gibb, died from a heart infection at age 30.
The Bee Gees scored pop hits with "I Started a Joke," "How Can You Mend a Broken Heart" and "Lonely Days" before turning to disco in the mid-'70s. Their music for the film "Saturday Night Fever" catapulted them to international superstardom with hits like "Stayin' Alive," "Night Fever" and "How Deep Is Your Love."
The trio were inducted into the Rock and Roll Hall of Fame in 1997.
Robin Gibb was born Dec. 22, 1949, in England. He and his brothers were raised in Manchester before the family moved to Australia, where they began performing on television shows.
In addition to his wife, Robin Gibb is survived by his daughter, Melissa and sons Spencer and Robin-John.