Just under three million people in Hong Kong will be able to apply to live, study and work in the UK when a new visa route opens on Sunday.
The government offered a pathway to British citizenship for those holding British National (Overseas) status and their eligible family members last summer.
It followed the imposition of a controversial new security law in Hong Kong by China, which has since been described by the UK as means to "crush dissent" against Beijing.
As with other visas, after five years in the UK, they will be able to apply for settled status - and after a further 12 months, they will be able to apply for British citizenship.
Prime Minister Boris Johnson said: "I am immensely proud that we have brought in this new route for Hong Kong BNOs to live, work and make their home in our country.
"In doing so we have honoured our profound ties of history and friendship with the people of Hong Kong, and we have stood up for freedom and autonomy - values both the UK and Hong Kong hold dear."
The government has previously declared China's new national security law a breach of the Sino-British Joint Declaration, the deal that saw Hong Kong pass back to China from Britain in 1997.
Foreign Secretary Dominic Raab said the government "won't look the other way when it comes to Hong Kong" and would "live up to our historic responsibility to its people".
And Home Secretary Priti Patel added that "global Britain will always stand up for what is right and uphold our commitments".
Approximately 7,000 people with BNO status and their dependents have already been granted "Leave Outside the Rules" at the UK border over the last six months, prior to the opening of the new visa route.
The government estimates there are 2.9 million BN(O) citizens eligible to move to the UK, with a further estimated 2.3 million eligible dependents.
They expect up to 155,000 BN(O) status holders and their dependents to make use of the new visa route in the first year, and between 250,000 and 325,000 over five years.
From 23 February, those eligible with a biometric passport can apply online and then use a smartphone app to scan their passport, instead of attending a visa application centre.
The visa fee payable to stay for five years will be £250 per person or applicants will also be able to apply to stay for 30 months which will cost £180 per person.
This is lower than many other visas.
Applicants will be expected to be self-sufficient and will need to show that they can accommodate and sustain both themselves and their dependants, for at least six months upon arrival to the UK.
They must also have no serious criminal convictions.