The £400m valued firm has appointed Buchanan Communications, having previously used Merlin PR.
Buchanan won the retained brief via a competitive pitch thought to have included the incumbent as well as Brunswick and Pelham Bell Pottinger.
Allied Gold produces gold from two mines, one in Papua New Guinea and one in the Solomon Islands.
The firm has announced it is looking to more than treble its gold production from the current run rate of 70,000 ounces a year to more than 220,000 ounces over the next 12 months.
Allied was listed on AIM in 2006 and stepped up to the LSE's Main Market last week. The firm's primary listing is in London, with secondary listings in Toronto and Australia, and it is aiming to become a constituent of the FTSE 250.
Bobby Morse, senior partner at Buchanan, commented: 'Allied Gold is one of those hidden gems you come across only once in a while - it has a strong management team, is highly profitable, growing rapidly and operating in a very strong gold price environment.
'We think this is an investment proposition that will get substantial traction in the market over the coming months.'
The company's Simberi gold mine is 85 kilometres from Lihir Island in the Tabar Islands group in Papua New Guinea, which commenced production in 2008.
Allied Gold picked up Gold Ridge in the Solomon Islands in late 2009 when it acquired Toronto-listed Australian Solomons Gold.
Buchanan has built a strong track record in the mining sector with a precious metal portfolio that includes Centamin Egypt, Archipelago Resources, Avocet Mining and Eastern Platinum.