There were several people who influenced Thurber throughout his lifetime, for better and for worse. These friends and acquaintances taught Thurber about himself, his audience, and the relationships between the two. In many ways, his friends where what kept him alive for so long.

One person very central to Thurber's life was Elliot Nugent, a fellow student at Ohio State University. He was one of Thurber's influential mentors who saw the genius within him and helped encourage it to come out. Nugent was impressed by Thurber's wit from the moment they met. Over the years, Nugent remained Thurber's confidant, and in 1939, he helped Thurber write a successful Broadway play entitled The Male Animal.

Harold W. Ross was also an important person to Thurber. Ross was the founder of The New Yorker. Ross hired Thurber in 1927, and Thurber never left. After Ross's death, Thurber wrote what he thought would be a popular memoir of the man. But it received mixed comments after its publication in 1959, many of them negative. Nevertheless, Ross and Thurber shared a special friendship that lasted for many years.

Another close friend of Thurber's was Elwyn Brooks White, a fellow staff writer at The New Yorker. E. B. White, like Nugent, found Thurber's humor to be wonderful, and was very accepting of Thurber's work. The two men shared many times together, until Thurber's The Years with Ross was published. After reading the book, both White and his family thought that Thurber's description of Ross was inaccurate and distasteful, and the friendship between them essentially ended.