The commission is one of the first public bodies to move to the city after the government's Lyons review on the relocation of public bodies in 2004.
Up to 200 jobs will be created when the Victoria Square office becomes fully operational later this year.
Richard Caborn, Minister for Sport and Gambling, is attending the opening.
'Thriving city'
Gambling Commission chairman Peter Dean said: "Birmingham was the clear frontrunner in our search for new headquarters.
"We have been absolutely delighted with the calibre of staff who have joined us, and over the next few months we will be advertising a range of additional vacancies."
Councillor Mike Whitby, leader of Birmingham City Council said: "This is a thriving city and I know the commission will be a great asset to Birmingham's growing professional services sector.
"I am confident that they will feel at home in the city and hope that this move will encourage other businesses to move here."
Earlier this year, a shortlist of eight possible sites for Britain's first Las Vegas-style "super-casino" was announced.
Local authorities short-listed for small and large casino licences in the West Midlands are Dudley, Wolverhampton, and the NEC in Solihull.
Up to 200 jobs will be created when the Victoria Square office becomes fully operational later this year.
Richard Caborn, Minister for Sport and Gambling, is attending the opening.
'Thriving city'
Gambling Commission chairman Peter Dean said: "Birmingham was the clear frontrunner in our search for new headquarters.
"We have been absolutely delighted with the calibre of staff who have joined us, and over the next few months we will be advertising a range of additional vacancies."
Councillor Mike Whitby, leader of Birmingham City Council said: "This is a thriving city and I know the commission will be a great asset to Birmingham's growing professional services sector.
"I am confident that they will feel at home in the city and hope that this move will encourage other businesses to move here."
Earlier this year, a shortlist of eight possible sites for Britain's first Las Vegas-style "super-casino" was announced.
Local authorities short-listed for small and large casino licences in the West Midlands are Dudley, Wolverhampton, and the NEC in Solihull.