Born in Young, New South Wales, he received a primary education before becoming a road contractor and dam sinker. He also selected land at Thuddingra. In 1914, he was elected to the Australian House of Representatives as the Labor member for Werriwa, defeating Liberal Member of Parliament Alfred Conroy.
Lynch was one of the Labor members who followed Prime Minister Billy Hughes when he left the Labor Party in 1916 and formed the Nationalist Party with the Liberals.
He became a farmer and rural writer before his death in 1941.