Judge Amanda Cohen ordered the airline to pull the plug on the racy advertising for its popular Girls of Ryanair charity calendar after complaints brought forward by Spanish consumer and women's groups.
In a non-binding ruling, Cohen praised Ryanair for its charity work but said online advertising of the annual calendars with pictures of flight attendants in bikinis was "discriminatory to women", local daily Diario de Sur reported.
During the court hearing, Cohen also called time on the airline's 2012 "Sizzling prices! And sizzling staff!" publicity campaign, which advertised cheap tickets with images of women in bikinis.
There was a "complete disconnection" between the images and the items on offer, the judge said.
She ordered the budget airline headed up by the charismatic Michael O'Leary to stop both publicity campaigns and ruled her decision would have to appear in two national newspapers.
But Ryanair plans to appeal the decision that affects advertising of a calendar which has earned €700,000 ($963,000) for various charities.
"This case and ruling only relates to specific adverts run in November and December 2012 and has no effect on Ryanair's continuing charity work or our current 2014 cabin crew charity calendar," said the airline in a statement sent to The Local via email.