Air Canada has been ordered to pay a French-speaking couple 21,000 Canadian dollars ($15,700) and write them a letter of apology for violating their linguistic rights.
Ontario couple Michel and Lynda Thibodeau filed 22 complaints against the airline in 2016, the BBC reported on Saturday.
Among them, they argued that the word "lift" was engraved on the buckles of their seatbelts in English but not in French, while French translations of words such as "exit" were in smaller characters.
They also said the English-language boarding announcement for their Montreal-bound flight was more thorough than the French version.
A Judge ruled on Friday that the airline had breached Canada's bilingualism laws.
In the ruling, the Judge agreed that the airline had "not upheld its linguistic obligations".
Air Canada reportedly told the court it would work to replace the signs.
The flag carrier is subject to the country's Official Languages Act, which seeks to ensure that English and French are given equal status.