"Have You Never Been Mellow" is a popular song written by John Farrar and recorded by Olivia Newton-John as the title track for her album of the same name.

In March 1975 the single became Newton-John's second consecutive number one hit on the U.S. Billboard Hot 100, although it stayed in the top chart position for just one week. The record also received a Grammy nomination for Best Female Pop Vocal Performance. The song also topped the Billboard Hot Adult Contemporary Singles chart and — in her continued success as a crossover artist — peaked at No. 3 on the Hot Country Singles chart.

The song is being performed as part of the 2007 Broadway musical Xanadu.