The building of the long-awaited Gungahlin Mosque was plagued by years of delays after a group fought its development approval through the courts.

The mosque officially opened on Sunday and will service North Canberra's growing Muslim population, which is estimated to be 5000 to 6000 strong. The community had been using a demountable shed on The Valley Avenue site as a temporary mosque.

Canberra Muslim Community president Mainul Haque said the $2 million mosque came after years of hard work.

"There was just a sense of absolute sheer joy and elation when it finally opened," he said.

The only other mosque for Canberra's estimated 10,000 Muslims is in Yarralumla and was built in 1962 and only has a capacity of 300 people.

Planning for the Gungahlin mosque began in 2001 and building approval was granted by the ACT planning authority in 2012.

But that same year Concerned Citizens of Canberra Inc appealed the mosque's building approval. It lost the fight in 2015 and earlier this year was ordered to pay the ACT government's legal fees.

Mr Haque said while there had been some opposition to the mosque, the greater Gungahlin community and both sides of government had been largely supportive.

He said the nearby Uniting Church had been instrumental in its support for the mosque in the face of opposition.

He said the mosque had been built entirely on community donations and would serve not only as a place of worship but an important community space. "If anyone has questions please come and visit us we are open, our mosque is open to anybody," Mr Haque said.

"You will see we're just mums and dads and neighbours like everyone else."

The mosque held a community open day to celebrate the opening and encourage the community to come and visit.

"Nothing in Australia happens without a backyard BBQ where you invite friends to spend time," Mr Haque said. "This is what we wanted to do, to share our mosque with our friends and neighbours and community."