"If You Love Me (Let Me Know)" is a song written by John Rostill that was a 1974 hit single for Olivia Newton-John. It was her second release to hit the top 10 in the United States, reaching number 5 on the pop chart and number 2 on the Easy Listening chart. It also reached number 2 on the Billboard country chart. As with her single "Let Me Be There", Mike Sammes sings a bass harmony. It was nominated for the 1974 Country Music Association Award for Single of the Year.

Dame Olivia Newton-John was a British and Australian singer and actress. She was a four-time Grammy Award winner whose music career included fifteen top-ten singles, including five number-one singles on the Billboard Hot 100 and two number-one albums on the Billboard 200: If You Love Me, Let Me Know (1974) and Have You Never Been Mellow (1975). Eleven of her singles and fourteen of her albums have been certified Gold by the Recording Industry Association of America (RIAA).