Davy Jones -- lead singer of The Monkees -- has died ... TMZ has learned.
An official from the medical examiner's office for Martin County, Florida confirmed with TMZ they received a call from Martin Memorial Hospital informing them that Jones had passed away.
We do not know the circumstances surrounding his death.
Jones is survived by his wife Jessica and 4 daughters from previous marriages. He was 66-years-old.
Jones joined The Monkees in 1965 ... along with Micky Dolenz, Michael Nesmith and Peter Tork ... and together they churned out a bunch of hits including, "Daydream Believer," "Last Train to Clarksville" and "I'm a Believer."
The group was initially cast by TV producers who wanted to create a scripted series about an actual rock n' roll band.
Davy's last performance was on February 19th in Oklahoma -- the night before, he performed at BB King in NYC ... and he looked totally fine.