Smith was born to British immigrants in Selukwe, a small town in the Southern Rhodesian Midlands, four years before the colony became self-governing in 1923. During the Second World War, he served as a Royal Air Force fighter pilot. A crash in Egypt caused debilitating facial and bodily wounds that remained conspicuous for the rest of his life; following rehabilitation, he served in Europe, where he was shot down and fought alongside Italian partisans. He set up a farm in his home town in 1948, and the same year, became Member of Parliament for Selukweat 29 years old, the country's youngest ever MP. Originally a Liberal, he defected to the United Federal Party in 1953, and served as Chief Whip from 1958 onwards. He left that party in 1961 in protest at the territory's new constitution, and in the following year helped Winston Field to form the all-white, firmly conservative Rhodesian Front, which called for independence without an immediate shift to majority rule.