- The author and protagonist of the Autobiography
; he writes the work ostensibly to tell his son about his life and to provide a model of self-betterment for anyone interested. Born into a modest Boston family, Franklin moved to Philadelphia in his late teens and eventually opened up his own newspaper, The Pennsylvania Gazette.
tells of the major events of his life and many of his important scientific and political ideas, but the work does not discuss the American Revolution, in which Franklin was a major participant.
- Benjamin's son and royal governor of New Jersey in 1771 when Ben begins writing the work. Ben begins the Autobiography
as a letter to William with the intent of telling him about his life.
- Ben's parents were named Josiah and Abiah. Abiah is mentioned very little. Josiah's second wife, she mothered ten children with him. Ben was the eighth of these children. Josiah took a large interest in Benjamin, teaching how to debate and how to write effectively. Ben respected him enormously. After both parents died, Ben had them buried and erected a monument to them in a prominent Boston cemetery.
- Franklin older brother who owns a printing house in Boston. Ben is apprenticed to James when Ben is 12, and while they do not always get along very well, Ben learns much from James and proves to be quite helpful. When James is arrested for holding subversive political ideas, Ben takes over the paper until James' release. When Ben breaks his contract and leaves for Philadelphia, James grows angry and spiteful.
- A "bookish lad" whom Ben befriends in Boston. They two practice their debating skills in Boston. John resolves to go to Philadelphia with Ben several years later, but his plans evaporate when he becomes an alcoholic and ends up moving to the Caribbean. Ben loans him a large amount of money which Collins never repays.
- A printer in Philadelphia, he is unable to hire Franklin but he does allow Franklin to stay in his house. Later on, when Franklin runs his own paper, the two are competitors until Bradford leaves the printing industry.
- The printer in Philadelphia for whom Franklin works. Their relationship deteriorates over time, and eventually they have a falling out. Keimer, however, tries to make amends when he realizes that Ben can supply him with important printing tools.
- A resident of Philadelphia, he houses Franklin shortly after Franklin arrives in Philadelphia.
- The daughter of John Read, she eventually marries Franklin even though their courtship is interrupted by his 18-month trip to England, during which time she marries another man who disappears--thus allowing her marriage to Franklin.
Gov. William Keith
- The royal Governor of Pennsylvania when Franklin arrives in Philadelphia. Keith is impressed by Franklin and resolves to help him, but in effect does very little. He is a man who does not often follow through on what he says he will do.
- A local Philadelphia poet whom Franklin befriends and with whom Franklin travels to England. Franklin tells a story of a time when Ralph, who was often disliked and thus overly criticized by his friends in the realm of poetry, asked Franklin to read one of Ralph's poems as Franklin's own, which Franklin did to very high praise. Ralph traveled with Franklin to England, where he leeched off Franklin most of the time and borrowed large sums of money that he never repaid. Franklin and Ralph ended up going separate ways when Franklin hits on Ralph's girlfriend and is rejected.
- A friendly Quaker whom Franklin meets on his way to England. They remain friends while in England, and it is Denham who eventually convinces Franklin to return to America after an 18-month stay. Franklin works for Denham for a short time in a goods store upon his return.
- The man with whom Franklin begins a new printing house after leaving Keimer. Meredith, however, does not work very hard, and eventually leaves.