He was the oldest of six children of Gemima Howan and Augustus Walsh, who got married at
Foxton around 1894. He was educated at Foxton Primary School,
Palmerston North Boys' High School and
Wellington Technical College. He then became a farmer in
Waikato and became involved with
Federated Farmers. He was chairman of the meat and wool section and also on the executive of Federated Farmers from 1941 to 1957. He joined the
National Party and was on the party's dominion council and executive and Waikato divisional chairman from 1946 to 1951 before being selected as a parliamentary candidate. He represented the
Tauranga electorate from the to 1972, when he retired. At the 17 October 1962 meeting of the New Zealand Parliament's External Affairs Select Committee, Walsh was elected to chair the committee, on the motion of Defence Minister,
Dean Eyre. ==Honours and awards==