The term 'Ferris Bueller's Girlfriend' refers to Sloane Peterson, a character from the 1986 movie Ferris Bueller's Day Off. Sloane is portrayed by actress Mia Sara and is the girlfriend of the titular character, Ferris Bueller. She is a rebellious and independent young woman who is willing to take risks and stand up for herself. Sloane is a loyal friend to Ferris and helps him in his schemes. She is also a fashionista, often seen wearing stylish clothes and accessories.