Todd Anderson is one of the two deuteragonists (alongside Neil Perry) in the 1989 film Dead Poets Society. He is a shy, quiet, and reserved student of Welton Academy, and the younger brother of the popular Welton alumni and distinguished scholar Jeffrey Anderson.
He is arguably the most dynamic character, as he plays an important character development role in which he intends to shed away his shyness to become a young man who stands up for what he believes in. However, after his roommate Neil died of suicide, he manages to break out of his shell, becoming his own person in the end.
Todd is an example of a stereotype shy kid. When he first appears at the start of the film, Todd barely speak his name, let alone speak in front of groups of people or his class. He shows evidence of performance anxiety, something that interests his English teacher John Keating, which Todd plays an important character development throughout the film.
Despite being extremely shy and introverted, Todd shows a great deal of appreciation for his friends, particularly Neil. This is shown when Todd joins the Society despite being afraid of speaking in public and joining the boys on their various adventures, and the emotional turmoil he is shown in after the death of Neil.
Near the climax of the film, when Keating's job security is in danger, Todd stands up for him against Cameron, saying "That is not true, Cameron and you know that! He didn't put us up to anything. Neil loved acting!". Later at the end of the film, Todd finally shed away his shyness and encourages himself and his fellow DPS members to rebel against Mr. Nolan to honor Keating who was about to leave Welton permanently.
Upon arrival at Welton Academy during the start of the film, Todd sits with his parents at the opening ceremony, where he is urged by his father to stand with the rest of the boys during the reciting of the four pillars. After the ceremony, Todd follows his mother and father up to greet Headmaster Gale Nolan, who speaks of Todd having "big shoes to fill", in reference to his older brother Jeffrey. Todd later runs into Neil Perry on the way to his room, who says they're going to be roommates. Neil questions why Todd left his old school, and Todd again mentions that his brother formerly attended Welton.
Todd continues on to his and Neil's dorm room, where he walks in on Richard Cameron calling him a "stiff". Neil then introduces Todd to Charlie "Nuwanda" Dalton, Knox Overstreet, Gerard Pitts and Steven Meeks, four friends who also comment on Jeffery's reputation at Welton, noting that he was a valedictorian and National merit scholar. Todd witnesses them mocking the school right before Neil's father interrupts and calls Neil outside. As the boys leave Neil and Todd to their unpacking, Todd tells Neil that his parents wanted him to become a lawyer just like his brother, but doesn't have the courage to tell them that he instead wanted to be a writer. The boys later invite Todd to join them in their study group, and Todd responds quietly with "thanks".
Todd is present for Mr. Keating's first lesson on Carpe Diem in the hallway, and appears to know answers to several of Keating's questions but fails to say anything. While he speaks little, it appears he enjoyed the lesson. Later, after another interesting lesson from Keating, Todd accompanies the boys in finding out what Keating's "Dead Poets Society" was. He appears interested in Keating's love of poetry and amused by his stories. When Neil asks if Todd will join them in reconvening the Dead Poets Society, Todd reluctantly agrees on the grounds that he won't have to speak at the meetings.
Later on, Todd's character development plays an important role in the film: In which Mr. Keating tells him to stand up and recite his own poems. By pulling the boy out of his seat in front of the class and create his own poem, Todd finally manages to build his confidence in front of his fellow DPS members and other classmates, all thanks to Mr. Keating. Todd's character later improves when Neil finds him sitting alone and disappointed and boosts his roommate's confidence by telling him that he should take the desk set and throw it to see how aerodynamic it is.
However, after Neil committed suicide following Thomas' forceful decision to send his son to Military school after the school play, Neil's death affected Todd the most out of all DPS members (including Keating), emotionally and repeatedly stating that Mr. Perry killed his own son, and that Neil would never leave them as he runs towards the snowy lake, screaming Neil's name as he goes farther alone.
Later, When the traitorous Richard Cameron insensitively justifies that he along with Mr. Perry falsely accused Keating on Neil's death as well as disrespecting Neil's life-dream of becoming an actor, Todd dramatically retaliate at Cameron that Keating would never endangered any of the members with his teaching methods, and Neil truly loved acting more than being a doctor, but to no avail.
Following Dalton's expulsion for punching the betrayal Cameron, Todd was summoned by Mr. Nolan with his parents waiting in his office. Nolan asks if Todd was a member of Dead Poets Society, and he admits he was. Nolan reviews the details of the Society’s meetings, and says that Mr. Keating’s influence as a teacher is what led to Neil’s death. Nolan gives Todd a confession letter that will dismissed Keating from his job as a teacher, and asks Todd to sign it as confirmation that it’s true. The signatures of his friends are already on it, while Todd asks what will happen to Mr. Keating, his inpatient father (who is on the same page as Neil's father Mr. Perry) forces his son to sign it immediately otherwise face consequences.
After Keating is fired, Todd and his classmates are now under Mr. Nolan's teaching at English class for the time being, with Cameron received an undamaged poetry book following Keating's orders to rip the essay out. As Keating was about to leave the school, Todd confesses to Keating that Neil's death wasn't his fault and they were forced to sign the confession letter by school administration as well as their parents, which the former teacher already knows as Nolan (along Mr. Perry and Richard Cameron doesn't believe Todd) demanded Keating to leave the campus immediately while ordering Todd to sit down and be silence, threatening him and the other students with expulsion if they made one more lie about Mr. Perry in his class.
Not wanted to be a coward any longer and done being ordered too far, Todd finally destroys his shyness completely and truly becomes his own independent person as he is the first to rebel against Mr. Nolan by standing up to his desk and called Keating: "O Captain! My Captain!". His fellow DPS members (excluding Cameron) was motivated by his courage, and later follows his footsteps to do the same, and with that, Todd's actions made Keating impressed as his work survived though the hearts of his loyal students at the end of the film.