Paxton has said that attending college is "very important" to her because "it is important to expand your mind." In 2006, Paxton applied to the University of Southern California's film studies program, and was not accepted. She has noted that she would like to major in business administration with a minor in history (as she is a "history fanatic") and to start a production company.

Paxton, who keeps a journal, has a dog named Jenny (who is eleven years old as of 2007), and a Chihuahua puppy named Coco Chanel. She is friends with her Aquamarine co-stars, JoJo and Emma Roberts, and lives "five minutes apart" from Roberts. Paxton has credited her Jewish religion for feeling "very connected" to her family, who keep her "grounded" and are "always number one" in her life. She did not have a Bat Mitzvah because she was busy filming, though she has said that she "wanted to so bad."