Marcus Pfister (born 30 July 1960 in Bern, Switzerland) is a Swiss author and illustrator of children's picture books.

[1] His Rainbow Fish series of children's picture books, published since 1992, has been a worldwide success.

[2] Decode Entertainment turned the picture books into a 26-episode animated television series of the same name, which has aired on the HBO Family television channel in the United States since 2000.

[4] In February 2017, he was the featured speaker, author, and illustrator at Nepal's first children's literature festival, Bal Sahitya Mahotsav.

Marcus Pfister lives with his wife, Debora, in Bern, Switzerland.