Girardeau is a French surname. Notable people with the surname include:
Émile Girardeau (1882–1970), French engineerJohn Girardeau (1825–1898), American Presbyterian minister and theologianMarvin D. Girardeau, quantum physicist, currently a research professor at the University of ArizonaW. L. Girardeau, trustee of Stanton College Preparatory SchoolIsabella Girardeau, opera soprano in the 1711 premiere of RinaldoFrank Girardeau, actor who had a guest appearance on Law & Order: Criminal Intent episode "No Exit"