Alvin Seville is one of the Chipmunks and the main protagonist of the series and movies, as evidenced by his name being part of the titles. He is the leader of The Chipmunks as well as the middle child, he is the self-proclaimed "awesomeness" one.
Alvin continues to relish to much his role as band front man, and his antics at a charity concert land Dave Seville in the hospital.Much to Alvin and his brothers charging Dave orders them to leave pop stardom behind and enroll school. But Alvin's popularity at school doesn't sit well with Simon and Theodore, when Alvin lets them down at the big sing off against the Chipettes.
Alvin has been shown at times to be quite self-absorbed and greedy, but at others to be selfless, and giving. Alvin is an emotional roller coaster, his enthusiasm endless, and despair bottomless. The term "look before you leap" does not apply to Alvin, who is spontaneous and impulsive. Alvin is the oldest of the three Chipmunks as revealed to us on the episode "Grounded Chipmunk". After making the statement, "I've never been alone, except those five minutes before Simon was born", ironically he was the smallest chipmunk in The Alvin Show.
Alvin has a love/hate relationship with Brittany, as they often find it hard to be with each other due to their clash of egos. He is voiced by Justin Long (Ross Bagdasarian, Jr. in other shows, and formerly by Ross Bagdasarian, Sr.)
In the 80's series, it was revealed that their mother abandoned his brothers and himself at Dave Seville's house, due to a terrible storm and finds himself unable to forgive her until the end of the episode. In the live action film, he and his brothers are living in is cut down and used as a Christmas tree at the place Dave Seville works. His brothers and himself jump into a basket, which is given to Dave. Dave brings the basket home, where Dave discovers the Chipmunks after a prolonged game of hide and seek as well as being knocked out with a jar.
Alvin is impulsive, charming, musical and full of animal magnetism. The character, who is heavily based on former member James Sawyer always seems to make up hare-brained schemes to get what his goal at the time is, whether it be trying to help his brothers, or keeping Dave from figuring something out, or getting out of a sticky situation. However, Simon seems to refer to his often illogical or crazy plans as "challenging the ordinary".
Alvin's signature color is red with a large yellow A, and he has blue eyes in the 80s series and brown eyes in the live action film. In the 80s series, he has light blue shoes; In Alvin and the Chipmunks Meets Frankenstein and Alvin and the Chipmunks Meets the Wolfman, he has dark blue shoes. He plays the guitar, piano, and harmonica, among many others. Although Alvin is very much self-centered, he does care about his brothers. In Alvin and The Chipmunks Meet the Wolfman, Alvin helped Theodore temporarily get a bully off his case, causing the principal to remark, "I'll say this for Alvin: he sticks up for his little brother." Alvin holds the place as the leader of the Chipmunk trio. He and Brittany Miller one of The Chipettes have a love-hate relationship. According to "A Chat With Alvin", he cannot pronounce Ross Bagdasarian, Jr.'s last name correctly, which, at the end of the track, gets him yelled at by Ross, Jr. In the 2007 film Alvin and the Chipmunks, he is voiced by Justin Long. In the movie he describes himself upon meeting Dave as 'the awesomest one'. He also wears a red hat. However in the 2007 movie "Alvin and the Chipmunks" Alvin is only seen wearing it twice; the first time on a magazine cover, and the second at the end of the movie.
Alvin has always possessed a impulsive behavior which at times have irritated or angered others around him most obviously Dave. At times Alvin's determination can be viewed as being thoughtless, greedy or manipulative. However he has also been shown to show kindness such as when he gives away his harmonica one of his most prized possessions to a child with terminal illness. As a result of his constant habit of reacting to opportunity Alvin has gotten his brothers or himself in trouble quite a few times such as The balloon race in the Chipmunks Adventure. Alvin has also been shown to have difficulty at showing affection such as in the film Alvin and the Chipmunks where he initially struggles at telling Dave that he loves him as a father before finally bursting out in a prolonged speech that about how much he loves Dave. Alvin has also been shown to be a charming member of the trio. Such as in the Valentine special episode where he dresses stylishly and attempts to swoon a group of visiting girls before being usurped by Simon who drank a special kind of elixir which granted him natural magnetism and charm; in Alvin and the Chipmunks: The Squeakquel where he manages to capture the attention of a group of girls using his cute looks and as well as the French language (e.g. he called a blonde girl 'Mademoiselle' after kissing her fingers.