It allows people to access information from public bodies such as the States, with some planned exceptions such as public utility companies.
Requests costing less than £50 in labour will be free but others may cost up to £500.
If it costs more than that to gather the information, the requests may be refused.
Constable Juliette Gallichan's committee drew the Jersey law up.
She said it would make the government more transparent and hoped it would encourage more interest in politics.
"This gives a right to information unless that information is in the absolute exempt category. But public, official and statistical information, the costs of doing various things can be accessed, but not information like 'does Mrs Smith have a house in St Mary?'"
"Knowing that people can get to the heart of the information they are looking for will make them realise that the government is not always trying to hoodwink them or to keep them in the dark but certainly if a government is going to be open then hopefully that will engender some closer feeling with the community."
James Leaton-Gray, who is in charge of the BBC department that looks after Freedom Of Information requests, thinks the law will be a good thing for Jersey.
"It is part of balancing up of making sure the government you elect can be held accountable," he said.
"But it will be inconvenient and sometimes expensive for that government and in the end when it is expensive, that is your money it is spending."
In the UK, the MPs' expenses scandal arose from a Freedom of Information request.