d'Ancona succeeds Boris Johnson, who was in the post for six-and-a-half years before resigning when he was made shadow higher education minister.
Andrew Neil, chief executive of The Spectator, said: "Matthew is already one of Great Britain's foremost political commentators and I am in no doubt he will now become one of Britain's foremost editors.
He combines the requisite political gravitas and insight with the wit and originality that the post requires."
d'Ancona added: "I have great ambitions for the title, and am fortunate to inherit from Boris Johnson a magazine that has never been more successful.
"Under my editorship, I want The Spectator to adapt its fine traditions as a source of superb writing, news exclusives and wit to a new and exciting political landscape. It will be modern, free-thinking and indispensable."