Walker, currently editor of Nuts.co.uk and Mousebreaker.com, will join Future on 1 April.
He has more than 13 years' digital experience and during his time at IPC has taken Nuts.co.uk from number three to number one in the men's lifestyle market.
Walker will be tasked with developing and delivering strategy to drive online traffic and revenue, reporting directly to group publishing director Simon Maxwell and working closely with Future's US operation.
He will work across Future's digital Entertainment portfolio, which comprises multi-media brands such as CVG, Games Radar, Total Film, Edge and PC Gamer.
Walker said: "I have a clear vision of where Future can expand and grow its already really impressive audience reach of games and film enthusiasts. I can't wait to get started."
Maxwell said: "Keith's experience in driving site performance, coupled with his deep understanding of the young male audience make him an ideal appointment as we look to continue to build our brands on a global scale.
"This move highlights our focus on driving further significant growth of our digital brands alongside our extensive offering of print, tablet and on console business."