The scheme in Glasgow is said to be the first in the UK and the city council hopes it will "halt the rise of high-cost payday lenders".
Dubbed Glasgow's Starter for Ten, 4,000 S1 pupils will be eligible to use the account with an initial deposit of £10 in each one.
The project was launched by council treasurer Paul Rooney at Lochend Community High School in Easterhouse and it is part of an overall scheme by the council to promote credit unions over loan companies.
Cllr Rooney said: "What we want to do with this project is give every young Glaswegian a safe and secure relationship with a credit union that is responsible to its members and to its community.
"Straight away, they will start to learn about managing money and will have the opportunity to save.
"And if, years from now, they decide they need to borrow; they will also have access to a lender that knows them well and will help them - rather than simply see them as an opportunity to turn a profit."
A council group studied the impact of payday loans last year and proposed a range of measures to promote credit unions, including the Starter for Ten scheme.
The council said it will not lease any of its commercial property to payday lenders and it has blocked computers on its networks from accessing payday loan websites.
Meanwhile, credit unions are being encouraged to be more visible in communities with the council offering rent subsidies and rates relief.
Cllr Rooney said: "It is clear that many people who use a series of short, expensive loans actually need longer-term credit, but often perceive it to be quicker and easier to get money with payday lenders.
"However, if someone already has a relationship with a credit union, then it can respond quickly and offer affordable, sustainable finance when it is needed.
"Just as importantly, it can also help them to save and manage their money well in the long term; which the payday lenders are just not interested in."