The agency won the business after a pitch that also involved LBi and Dare, and will now handle all of the digital advertising surrounding the venture, which aims to launch before the end of this year.
Project Canvas is a joint venture between the BBC, ITV, Channel 4, Five, BT, Talk Talk and, most recently, Arqiva, which signed up to the consortium in March.
Project Canvas will give consumers access to the participating broadcasters' video-on-demand offerings via a single set-top box, as well as allowing them to access the internet via their TV.
Studies have suggested that Project Canvas could reach 3.5 million homes by 2014; however, the venture still faces problems regarding the internet connection speeds and keeping the prices of the set-top boxes to a minimum.
Earlier this month, the Office of Fair Trading gave Project Canvas the green light after deciding not to investigate the proposal under the 2002 Enterprise Act.
Oystercatchers is currently handling a review of the company's advertising account, which kicked off in January.