Who is the longest standing rock band with no member changes?

The longest-standing rock band with no member changes is the American band UFO, formed in 1968. While they have seen several lineup changes throughout their career, the band has maintained the core lineup of founding members Phil Mogg, Andy Parker, and Paul Raymond until his passing in 2019. However, for a band with an unbroken lineup, The Rolling Stones and AC/DC are notable for having retained their founding members for decades, with only minor lineup changes over the years.