Mary Jane Crafoord Muus (10 June 1919 – 12 July 2007) was a Danish painter and illustrator. Most of her works portray people, either in portraits or walking about on streets or market places in foreign countries. She is remembered above all for her sensitive, realistic illustrations in a wide range of Danish books. One of Denmark's foremost 20th-century illustrators, she had a unique style of her own.