Decroix () is a surname. Notable people with the surname include:
Emile Decroix (1904–1967), Belgian racing cyclist Éric Decroix (born 1969), French footballer Jacques Joseph Marie Decroix (1746–1826), French writer and collector Julien Decroix, better known as Soan, (born 1981), French singer-songwriter Lieselot Decroix (born 1987), Belgian road cyclist Marjolein Decroix (born 1992), Belgian alpine skier
See also Delacroix Delcroix