Irish was the specials editor of Stuff, with responsibility for supplements and the website. He previously spent three-and-a-half years as the deputy editor of the Observer Sport Monthly.
Irish hopes to build on the circulation growth that Stuff enjoyed under Dunmore. The latest ABC figures saw Stuff climb above the 70,000 mark.
Future investment in the magazine will concentrate on improving its design and the quality of cover images, and will support more frequent themed supplements, along the lines of the recent Gear, which focused on winter sports and travel products.
Eddie Johnson, publishing manager of Stuff, said: "We're delighted to welcome Ollie to the team and we think he's the ideal man to take Stuff forward."
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