Power will work with WPP out-of-home agency Kinetic, Interpublic agency IPM and associated agencies. He will report to Lucinda Sharp, group head of StreetTalk.
Power left Scotland-based outdoor media owner Forrest Group to pursue other interests in June 2009 after his duties were absorbed by managing director Marc Keenan. He previously worked at Clear Channel Outdoor selling large format banners.
JCDecaux has also appointed Richard Mehta to the position of business development manager in the StreetTalk team working across Aegis out-of-home specialist Posterscope. Mehta joins JCDecaux from music magazine The Fly where he was sales executive.
Spencer Berwin, managing director of sales, said Power and Mehta will be an "invaluable addition to the StreetTalk team, bringing a wealth of experience to this youth-focussed brand".
Last year JCDecaux added 5,000 StreetTalk phone boxes and launched of targeted networks including StreetTalk Pharmacy, StreetTalk Couture and StreetTalk High Street Fashion.