AG Barr, which owns and produces UK soft drinks including Irn-Bru, Rubicon and Strathmore Water, has engaged the agency's consumer team after a competitive pitch.
The firm previously used Buchanan Communications.
Justine Warren, partner at College Hill, said AG Barr had a 'great story to communicate' and the agency would look to 'further develop this already successful company with its strong portfolio of growth brands'.
AG Barr has a history dating back 100 years and floated in 1965. Irn-Bru has a market-leading position in Scotland and is looking to grow the brand south of the border.
The group bought Rubicon, a range of exotic fruit drinks, in 2008.
