He was portrayed by Norman Lloyd.
History
The headmaster of the prestigious Welton Academy, Nolan is a severe, strict man, who governs Welton with an iron fist and has boundless respect for the school’s tradition. He sternly aims to entrench the 4 pillars of the institution (Tradition, Honor, Discipline, and Excellence) into the students' minds.
Nolan first appears at the beginning of the film reciting the traditional ceremony of Welton, and hires John Keating following the retirement of another teacher named Portius. He is later seen after the ceremony thanking the parents of Todd Anderson and Neil Perry, with the latter's father Thomas telling that he won't disappoint his son.
Nolan doesn't appear much until the second half of the film, where he had a hastily arranged school meeting discussing the profane unauthorized article about having girls to be admitted to Welton, and demands to find out who and what are Dead Poets Society members are. This lead to worsen consequences after one of his students Charlie "Nuwanda" Dalton, publicity pulled out a joke on having girls at Welton saying it's from God, and was paddled harshly by the headmaster at a private meeting for refusing to answer who are the members of the club.
Nolan later wants to have a discussion with Keating, who thinks highly of him at first and also told that Nolan used be an English teacher long before Keating, until he heard rumors of Keating’s unconventional methods, and begins to doubt on him, telling Keating not to have his students think for themselves and instead follow the academy's old traditions so that they can be prepared for college.
However, the news of Neil's suicide puts Nolan into serious cooperation starting with contacting the parents of each of his students (including Neil's), and later from the traitor Richard Cameron by revealing the members of the society with the help of Thomas. To make matters worse, Nolan expels Charlie for assaulting Cameron due to the latter's betrayal and ultimately succeeds by forcing Todd and all members of the Dead Poets Society to confirm and sign the document that lead to believe Mr. Keating is the scapegoat of Neil's suicide and that he is responsible for what happened with the help of their equally strict and uncaring parents, clearly showing that he cares more about his own personal success and the school's out of date traditions than any of the boys' lives.
As a result Keating is fired from Welton Academy and was barred from ever teaching again. Nolan is in temporary charge as English teacher until a new permanent teacher is found. He then gives a complete poetry book to Cameron, after finding out that most of it were rip out by the students at Keating's orders. When Todd told Keating of how he and his classmates were forced to sign the confession, Nolan orders Todd to be quiet and demands that Keating leave, threatening any other student who speaks up with expulsion.
Mr. Nolan appears powerless by the end of the film, when the DPS members, excluding Cameron, rebel against him by standing on top of their desks and calling out to Keating: "O Captain! My Captain!", leading to Nolan's emotional defeat, and that Keating's work had managed to survive. Thus, while Nolan may still teach the English class, Keating's influence amongst the DPS members remains, and this group of friends will never respect Nolan like Keating.
