72-year-old Laforêt, who first found fame as an actress in the 1960s, placed an ad on an internet site looking for someone to carry out some work on her terrace in 2009, reported daily newspaper Le Parisien on Thursday.
She specified in the ad that "people with allergies or orthodox Muslims" should not apply "due to a small chihuahua."
Laforêt claimed that she made the stipulation because she believed the Muslim faith saw dogs as unclean.
The case was taken up by anti-discrimination organization Mrap, which lodged a complaint against the internet site which ran the ad.
"To think that Marie Laforêt is racist is just stupid," said her lawyer, David Koubbi, according to the newspaper. He said the words in the advertisement were only a "warning."
Koubbi added that the star "has always shown her interest and admiration for the Muslim faith."
"She knew that the presence of a religion could conflict with the religious convictions of orthodox Muslims. It was a sign of respect."
Experts in the Muslim faith were quoted as rejecting the defence.
"Dogs are not considered unclean and it's false to suggest otherwise," said one quoted by the newspaper.