The Games, in which 5,000 athletes from 71 nations compete in 19 sports between July 27 and August 7, will be the biggest sporting and cultural event staged in the West Midlands.
Birmingham beat Liverpool in a truncated all-English race to host the event in December 2017 after original host Durban was stripped of the Games after running into financial problems.
Central government will provide three quarters of the funding (£594 million) with a further £184 million to be raised by Birmingham City Council.
The pot of public money will underwrite the city's preparations for the 11 days of sport and provide key funding for the Games' two main building projects: the redevelopment of Alexander Stadium and the construction of an aquatics centre.
"Having our budget confirmed is a key milestone for us and we can now look forward to delivering a fantastic Games for the people of Birmingham, the West Midlands and the country," Birmingham 2022's chief executive Ian Reid said in a statement.
The last time the Commonwealth Games were held in the UK, Glasgow was given £372 million of public funding for operational costs for 2014.
However, the Commonwealth Games Federation is keen to highlight that Birmingham 2022 should cost the British public £200 million less than Gold Coast 2018 cost Australians when operational and capital costs are considered.
Commonwealth Games Federation president Dame Louise Martin said: "We are pleased to have confirmation of the public investment in Birmingham 2022, which reinforces the Commonwealth Games' position as a cost-efficient multi-sport event focused on delivering numerous long-term benefits for the host city.
"An important element of the budget detail is the significant decrease in direct Games delivery costs compared to Gold Coast 2018."