Born in Sainte-Marie-de-Monnoir, Quebec, the son of George Ashby and Euphrosine Messier, Ashby was educated at the college of Sainte-Marie-de-Monnoir and the Université Laval at Montreal. He became a notary public in 1904 and practice in Lachine. He was elected to the Legislative Assembly of Quebec for the electoral district of Jacques-Cartier in the 1916 election. A Quebec Liberal, he was re-elected in the 1919 election and was defeated in the 1923 election. From 1923 to 1925, he was mayor of Lachine.