McAllister was born in West Berlin on 12 January 1971 to a Scottish father and a German mother. His father, James Buchanan McAllister, was a British civil servant, originally from Glasgow (where the family still has relatives). He had been stationed in West Berlin since 1969, attached to the Royal Corps of Signals. His mother, Mechthild McAllister, is a music teacher. David McAllister was raised bilingual (speaking English and German) and attended a British primary school in Berlin.