The son of Osborne & Little co-founder Peter Osborne, Osborne was born in Paddington and educated at Norland Place School, Colet Court and St Paul's School before studying at Magdalen College, Oxford. After working briefly as a freelancer for "The Daily Telegraph", he joined the Conservative Research Department in 1994 and became head of its political section. He went on to be a special adviser to Minister of Agriculture, Fisheries and Food Douglas Hogg and work for John Major at 10 Downing Street, including on Major's unsuccessful 1997 general election campaign. In Opposition, he worked as a speechwriter and political secretary to Major's successor as party leader, William Hague.