Mark Mueller (born July 11, 1957) is an American songwriter. A two-time winner of the ASCAP Pop Award for writing one of the Most Performed Songs of the year, he has had three Billboard Hot 100 Top Ten singles and one #1 Adult Contemporary hit. He co-wrote "Crush" by Jennifer Paige and "That's What Love Is For" by Amy Grant and wrote both words and music for the "Nothin' At All" by Heart. Born in the Bay Area and a graduate of University of California, Berkeley, he now lives and works in Los Angeles, California.