Louis Edgar Clark was born in Hackney on Christmas Day 1876 to Ellen Louisa (nee Maidment) and Octavius Thomas Clark. He was baptised as Louie Edgar Clark at St John the Baptist, Hoxton, on 18 March 1877. Louis is first noted as "artist" on the 1901 census, working from home with his artist father in Islington. Like Octavius, he is not known to have exhibited with any of the major art societies. There are also few auction records for him - mostly views of rivers and mountains. It is likely that he produced unsigned landscapes for the American market, as his younger brother Stanley is known to have done.
In 1904 Louis married Lilian Tees and they lived in Hertford Road, Lower Edmonton, Middlesex. They do not appear to have had any children. Louis died aged 46 at his home on 6 December 1923, he had been suffering from cancer.