Marc Shaiman (born October 22, 1959) is an American composer, lyricist, arranger, and performer for films, television, and theatre.

Shaiman was born in Newark, New Jersey, the son of Claire (née Goldfein) and William Robert Shaiman. He lives in both Los Angeles and New York City. Shaiman and Scott Wittman have been partners in life and collaborators in theater since 1979.

Shaiman started his career as a theatre/cabaret musical director. He then became vocal arranger for Bette Midler, eventually becoming her musical director and co-producer of many of her recordings, including The Wind Beneath My Wings and From a Distance. He helped create the material for her performance on the penultimate Tonight Show with Johnny Carson. His work with both Bette Midler and Billy Crystal led to his involvement on their films.