Foreigners applying for marriage visas for the UK will have to be at least 21 years old from the end of this month.
Ministers say raising the age from 18 is needed to stop forced marriages and deter people from abusing the system.
The measure applies to both partners. Spouses will have to agree to learn English - with future plans for English tests before spouses get their visas.
Minister Phil Woolas said "it is important we protect vulnerable young people" and "avoid exploitation".
Other changes intended to tackle forced marriage means people will have to register their intention to get married before they leave the UK.
Shadow home secretary Dominic Grieve said - when ministers first suggested the plan in July - that they were following the Conservative lead on the issue.
From 27 November both parties in a marriage will have to be 21 before a marriage visa can be issued.
The government says the move is part of its efforts to "crackdown on forced marriage and on those who attempt to abuse the marriage visa route".
In a report published last year, the Home Office says "there are sometimes situations in which a young person is forced by family pressure into an unwanted union," with one party needing a visa to enter the UK.
Raising the minimum age to 21, would "allow the young people involved to have completed their education as well as allowing them to gain in maturity and possess adequate life skills," it added.
The Home Office is also releasing further guidance for business on its new points-based migration system, after complaints from the CBI that firms were confused about how it will work.
The restrictions covering skilled workers and temporary workers come into force on 27 November.
Mr Woolas said: "The points system means only the migrants with the skills Britain needs can come - and no more. It is also flexible, allowing us to raise or lower the bar according to the needs of business and taking population trends into account.
"Had the system been in place last year there would have been 12 per cent fewer people coming in to work through the equivalent work permit route."
In a further change, Mr Woolas said he would close the route to UK residence for retired people of independent means, which allows over 60s with an income of £25,000 a year and a connection to the UK to remain indefinitely, provided they do not take work.
Only about 20 people a year took advantage of this route to citizenship, a home office spokeswoman said. They will still be able to apply for a temporary five year visa, she added.
Mr Woolas said: "We recognise that those entering under the retired persons of independent means route are required to be self-sufficient.
"But ... these people may not have enough disposable income to match the demands they place on public services."
Liberal Democrat home affairs spokesman Chris Huhne said: "The increase in age limits for marriage visas is a welcome defence against abuses such as forced marriage.
"But we must also give more help to legitimate spouses to learn English so they can play a full part in society.
"Tighter controls on counting people in are undermined by not counting them out. Exit checks must be reintroduced immediately if we are to manage migration effectively."