Baillon is a surname of French origin. Notable people with the surname include:
Henri Ernest Baillon (1827–1895), French physician and botanist Louis Antoine François Baillon (1778–1851), French naturalist and collector Louis Charles Baillon (1881–1965), Falkland Islands field-hockey player Susan Janet Baillon (1957), a.k.a. Siouxsie Sioux, British singer-songwriter