Ejgil Clemmensen coxed the Danish four to win bronze at the 1912 Olympics in Stockholm. With only two boats in each race, they lost the semi-final against the eventual winner from Germany. Together with the loser of the second semi-final, the boat from Norway, they tied for bronze.
Ejgil came from a family of architects. His father Andreas and his older brother Mogens were both reputed architects. Ejgil and his twin brother Bodil were the youngest children of Andreas Clemmensen. Ejgil himself worked as a machine worker. With his wife Ellen Louise (née Haae Laub) he had one son.