Alan O'Day (born October 3, 1940) is an American singer-songwriter, best known for writing and singing "Undercover Angel," a song which was number 1 in 1977. He also wrote songs for several other notable performers, such as 1974's Helen Reddy number 1 hit "Angie Baby" and the Righteous Brothers' number 3 hit "Rock And Roll Heaven". In the 1980s he moved from pop music to television, co-writing over 100 songs for the Saturday morning Muppet Babies series, and in the 1990s he wrote and performed music on the National Geographic series Really Wild Animals.
O'Day was born in Hollywood, California, the only child of Earle and Jeannette O'Day, both of whom worked in journalism, for the Pasadena Star-News. Earle took newspaper photos and did publicity for the Palm Springs Chamber of Commerce. Jeannette wrote for the Star News, as well as being a schoolteacher in Thermal, California and other schools in the Coachella Valley.