Mullan studied at Rossall School, then read law at Clare College, Cambridge, graduating in 1934.
He joined the Royal Naval Volunteer Reserve in 1937 and was called up on the outbreak of World War II, soon becoming a lieutenant.
[1] At the 1945 Northern Ireland general election, Mullan unsuccessfully contested South Down for the Ulster Unionist Party.
He remained a member of the Ulster Unionist Council until 1960, when he became a magistrate.
This article about a member of Parliament representing a Northern Irish constituency is a stub.