Born in Paddington, he was the son of William Stephen Hyatt, a house painter, and Agnes née Pattendon.
The chairman of the North Paddington Conservative Association, in November 1946 he was elected to Paddington Borough Council as a councillor representing Lancaster Gate West ward. Re-elected in 1945, he resigned in May 1946.
In the meantime he had been appointed to fill a wartime vacancy on the London County Council in the representation of Paddington South on 1 May 1945 as a member of the Conservative-backed Municipal Reform Party. When elections were resumed in March 1946 he did not defend the seat, but returned to the county council at the 1949 election when he was elected as a Conservative Party councillor for the neighbouring division of Paddington South. At the next county council election in 1952 he was defeated, with the Labour Party gaining the seat.