Eleanor Miller is the third of The Chipettes, younger than Brittany and Jeanette. Her last name is Miller in the 80's cartoon, but she does not have a stated last name in CGI. It is presumed to be Seville because of The Chipettes being adopted by Dave.
Eleanor is self-assured, cute, sweet, confident, obedient, and extremely maternal. She is a gifted athlete, despite her larger physique. Eleanor is quite strong-willed and is far more likely than the timid Jeanette to stand up to her sister Brittany when she feels that she is wrong. Eleanor is blonde with brown eyes, and her signature color is spring green.
Eleanor gets on great with Theodore of the Chipmunks. They are very open about their relationship and have many similarities. For example, they both love food and are interested in cooking. Also, their signature colors are both green.
Eleanor has a much softer and childish personality; she acts almost exactly like Theodore, and seems extremely naive. She also has green eyes.
In the second film, Eleanor arrived, along with Brittany and Jeanette, in front of the residence of former big-shot manager Ian Hawke. He agreed to manage them, as well as adopting them. Eleanor expressed the most interest in meeting the Chipmunks, especially Theodore, but was discouraged to do so by Ian with his lies. After enrolling in West Eastman, she finally got to meet him face-to-face, falling in love with Theodore. She continued to show eagerness in hanging out and getting to know him and the other Chipmunks, but her hopes were constantly being squashed by her manager. Ian was very cruel to her, making a rude comment about her weight and making her feel bad about her height. She and Jeanette were pushed further away from Brittany because Ian showed favoritism toward her. Though she was hurt by this, she held nothing against Brittany and decided to keep quiet in order to reach their dreams of becoming big. Secretly, Eleanor got some time to talk to Theodore and how nice he was, which likely made her doubt Ian's words. Eventually, her and her big sisters refused to let Ian order them around when he threatened to break their bond and split them up. He threatened each of them, forcing them to comply. Fortunately, Alvin came to their rescue and they made it in time to participate in a concert for their school to raise money for the music department. The Chipettes leave Ian and choose to live under Dave's care and supervision.
Eleanor always stands up to Brittany when she tries to push Jeanette around, and always defends her when anyone says something negative. For example, refusing to help Brittany join a group that called Jeanette a 'nerd'.
Eleanor always stands up to Brittany when she tries to push Jeanette around, and is generally the only person that tries to stand up to Brittany (besides Alvin). The two of them do share a very nice sisterly relationship.
Theodore and Eleanor are the most open about their relationship. They spend lots of time together and enjoy the other's company. Theodore has given Eleanor a necklace. They are shown to be married as adults.