Brianna and Gabriella Montgomery (Madeline Zima and Andrea Avery) are villainesses from the 2004 teen movie A Cinderella Story. They were the daughters of Fiona Montgomery and the stepsisters of protagonist Sam Montgomery. They became Sam's stepsisters after their mother married her father Hal. After he died in an earthquake, Brianna and Gabriella became openly cruel to Sam, bullying her and treating her as a servant (much like their mother). They also constantly fought with each other, even doing so as children.
At school, the two were shown to be "fans" of classmate Shelby Cummings, most likely envying her looks and popularity. They also both had crushes on football star Austin Ames, as shown when they both intentionally made their cars dirty so they would have to go to the car wash Austin worked at with his father. For the Halloween homecoming, they dressed as conjoined Siamese cats (though the conjoined part was displeasing to Gabriella). When the two saw Sam leaving the dance as they were picked up by Fiona, they tried to get to the diner to catch her red-handed, but failed to arrive before Sam did.Later on, Brianna and Gabriella found out Sam was "Cinderella" (having met up with Austin at the dance after some time of online chatting) when Brianna snooped through Sam's computer and found the messages between them. Both sisters then tried to claim themselves to be Cinderella to Austin, but he didn't fall for their scheme and it dissolved into a fight in the car wash that left them both messes.
Afterwards, the evil stepsisters went to Shelby, claiming that Sam had been deliberately trying to steal Austin from her and had threatened to kill them if they said anything. They assisted Shelby in creating a skit to expose Sam's secret, embarrassing her in front of their entire school. But at the school's big football game, the wicked stepsisters were devastated when Sam and Austin reconciled and kissed. After it was uncovered that Hal had left the house and his diner to Sam in his will, Brianna and Gabriella had to recover Sam's acceptance letter to Princeton (which Fiona had tried to discard) and also worked alongside their evil mother in the diner to pay off her debts for lying about Hal's will. Their final scene of the movie showed them tripping up on the skates they had to wear while at the diner.
- Brianna and Gabriella were two of the film's four villainesses--the other two being Fiona Montgomery and Shelby Cummings. Interestingly, they are all in some way connected to each other, despite all of them doing vastly different things over the course of the movie.
- Madeline Zima also appeared on The Nightmare Room as the evil Alexis Hall.