Merete Hodne had risked up to six months in prison for religious discrimination for turning Ms Malika Bayan, 24, away from her hair salon in Bryne, a small town in south-western Norway, in October last year.
"The court has no doubt that the defendant acted intentionally, that she deliberately discriminated against Bayan by expelling her from the salon because she is Muslim," the court ruled.
It imposed the fine and also ordered her to pay 5,000 kroner in court costs.
Hodne intends to appeal against the decision, her lawyer told news agency NTB.
The 47-year-old hairdresser told the court she saw the headscarf as a political symbol representing an ideology that frightens her, rather than as a religious symbol.
"I see it as a totalitarian symbol. When I see a hijab, I don't think of religion, but of totalitarian ideologies and regimes," she told the judges.
According to the charge sheet, Hodne told Ms Bayan "she would have to find someplace else because she didn't accept (clients) like her".
The hairdresser initially refused to pay a fine of 8,000 kroner for religious discrimination, so the case went before the Jaeren district court on Thursday.
While Hodne acknowledged that she could have turned Ms Bayan away more courteously, she denied the charge of religious discrimination.