Rocky, a three-year-old cross-breed, has been at Domestic Animal Services waiting for adoption for 302 days as of Friday - a new record.
The dog with the last longest stay at DAS was Aero, a Staffie-cross, who was adopted by a Gungahlin couple in July last year after 259 days in the Canberra pound.
Domestic Animal Services adoptions coordinator Tara McMahon said there was nothing wrong with Rocky, who came to the facility as a stray.
In March, it will be a year since Rocky arrived at DAS and the team is hopeful he can find his forever home before then.
Ms McMahon said Rocky was energetic and would be a good fit for an active family looking for a dog with a lot of love to give. Equally, Rocky loved to snooze with his favourite toy after a bit of exercise.
"Anyone who loves the outdoors, who loves running, who loves exploring up in the bush tracks [would be perfect for Rocky]," she said.
"He loves the water and is a very outgoing dog who likes to be with his people and he enjoys life."
Rocky's greatest challenge may be simply he was not a purebred and didn't look a certain way, but he is a loveable dog with a big smile.
"He's just a mixed-breed with nothing [bad] that stands out," she said.
DAS has 35 dogs up for adoption, with seven dogs that have been in the facility for more than 160 days. DAS would keep them all until they were adopted, unless there was a deterioration in behaviour. It has a 98 per cent adoption rate.
Ms McMahon said Rocky had taken life in the shelter in his stride and had actually come out of his shell, after being quite withdrawn when he arrived.
"Rocky now holds the record for the longest stay, which is a bit sad," she said.
"There's nothing medically wrong with him, there's nothing physically wrong with him. He has a lot of love to give."
More details on dogs available for adoption from DAS are here.
