Career
He was an unsuccessful Irish Parliamentary Party candidate in the East Clare by-election in 1917, losing to Éamon de Valera. He joined Sinn Féin within a year. He opposed the Anglo-Irish Treaty in 1922.
He became a King"s Inns bencher in 1925.
In a Seanad Éireann by-election held on 28 September 1934, he was elected for Fianna Fáil to fill the vacancy caused by the resignation of Arthur Vincent, serving until the body"s abolition in 1936. He was Attorney General of the Irish Free State from 1936 to 1937 and reappointed under the new Constitution, serving from 1937 to 1940.
Maurice Healy in his memoir "The Old Munster Circuit" praised Lynch"s outstanding integrity and strength of character and, while he was not normally an admirer of Éamon de Valera, praised him for an inspired choice of Lynch as Attorney General.