Donleavy has been tasked with making the magazine more "service-led" and will oversee the website, which has recorded a 72.5% yearly increase in monthly unique user figures to 851,739 according to Dart figures unaudited by ABC Electronic.
However, he will have his work cut out. Like all titles in the monthly men's sector Maxim is fast losing readers.
Maxim's print circulation continued to drop in the last set of ABC figures to 107,687 copies, down 18.1% over six months and 26.3% over a year.
Dennis has also promoted Pete Muir, Men's Fitness editor, to editorial director across Maxim and Men's Fitness, and given him a place on its lifestyle titles board.
Donlevy said: "Maxim offers its readers fantastic digital content and I want Maxim magazine to offer more than you can find in any other mass market men's monthly or weekly magazine. The best, quirkiest news, investigative features, in-depth reviews, oh, and women that make you actually want to know them."