Tork was best known for his role as the bassist and keyboardist for the band The Monkees, which was originally created to start in a comedy TV show of the same name. Tork's sister, Anne Thorkelson confirmed the affable musician's death to The Washington Post. He was diagnosed with adenoid cystic carcinoma, a rare cancer affecting his tongue, in 2009.
Tork is the second member of The Monkees to die.
Some of Tork's friends and other celebrities close to Tork expressed their sorrow on social media.
A post on the musician's official Facebook page said they were sharing "the devastating news. with beyond-heavy and broken hearts".More news: The 'Super Snow Moon' makes an appearance over Cleveland
More news: ‘Empire’ Producers Consider Suspending Jussie Smollett
More news: Landon Collins' locker status a point of debate between media members
After their formation in 1966, the made-for-TV group had number one hits with I'm A Believer, Daydream Believer, and Last Train To Clarksville soon after they were established.
"We want to thank each and every one of you for your love, dedication and support of our 'boss.' Having you in our world has meant so very much to all of us". Tork split from the group shortly after their critically derided 1968 release "Head".
He nabbed the part, and by the mid-'60s he was on his way to stardom alongside Dolenz, Michael Nesmith and Davy Jones.
However, Tork rejoined The Monkees in 1986 for a 20th anniversary tour, and played with the band on numerous occasions over the years, including a string of 45th anniversary gigs in 2011. He struggled with alcohol dependency before kicking the addiction in the '80s.