Millen is a surname. Notable people with the surname include:
Ari Millen (born 1982), Canadian actor Corey Millen (born 1964), American ice hockey player Edward Millen (1860–1923), Australian politician Floyd Millen (1919–1998), American politician from Iowa Greg Millen (1957–2025), Canadian ice hockey player and hockey commentator-analyst Karen Millen, fashion designer Matt Millen (born 1958), American football player and executive Rhys Millen (born 1972), New Zealand rally and drifting driver Rod Millen (born 1951), New Zealand rally driver and vehicle designer Steve Millen (born 1953), New Zealand IMSA racing driver