His departure comes as the eight-year-old Fallon moves to strengthen its management line-up, with the promotion of Karina Wilsher to managing director and Mark Sinnock to director of strategy.
McLeod will bring to an end his 17-year creative partnership with fellow founding partner Richard Flintham in January 2007, when he will join Rattling Stick, the production company set up by the directors Danny Kleinman and Ringan Ledwidge.
Flintham will take overall responsibility for Fallon's creative output, working with the creative partners Micah Walker and Juan Cabral, both of whom were promoted to creative directors in June.
McLeod said: "Leaving Fallon and Rich is going to be weird, but I'm ready for a new challenge. Directing is the itch I've been wanting to scratch."
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