Wilden will take the new role of planning partner at Goodstuff, and will oversee all strategic output from the agency. This will include responsibility for Virgin Mobile, Dr Martens and Pepsi America's communications strategy.
A former head of creative solutions at Manning Gottlieb OMD, Wilden currently heads Naked's COI business. He will join Goodstuff in September.
Goodstuff has also appointed the Carat account director Lucy Wilkins as a senior strategist. Wilkins will work on Virgin Mobile, Filofax, Ann Summers and Knickerbox.
The agency, which launched two years ago, now employs seven strategists in addition to the founders, Andrew Stephens and Ben Hayes.
Stephens said: "These appointments will allow the part-ners more time to develop the agency. Simon and Lucy bring very different skills, but one thing that unites them is their talent and passion."