The agency has been awarded the commission by the Organising Committee for the games and charged with developing brand values, a brand personality and brand positioning for the Commonwealth Games.
The agency's work will form the crux of the Commonwealth Games's marketing communications.
Elmwood will base the branding on the ideas used in Glasgow's initial bid to host the games. Ideas it puts forward will be informed by key stakeholders and members of the public.
Mino Russo, Elmwood Scotland's business developer, said: "We're confident Elmwood will help ensure the Glasgow 2014 Commonwealth Games are unique and memorable and demonstrate the way in which an effective brand can engage people from all around the world."
John Donnelly, Glasgow 2014's marketing and sponsorship director, said: "The Glasgow 2014 Commonwealth Games will be the biggest sporting event the city and country has ever seen and we're delighted to appoint Elmwood to oversee the brand development for the games.
"We were impressed with Elmwood's approach to the brief and their understanding of the immediate task."
The games take place between July 23 and August 3, 2014.