Billen is a surname. Notable people with the surname include:
Andrew Billen (born 1957), British journalist and children's author Magali Billen, Belgian-born American geophysicist (born 1953), Belgian association football player for Royal Standard de Liège Matthias Billen (1910–1989), German footballer Michael Billen (1955–2022), German politician Valère Billen (born 1952), Belgian football coach