Walter Shandy  -  Tristram's philosophically-minded father. Walter Shandy's love for abstruse and convoluted intellectual argumentation and his readiness to embrace any tantalizing hypothesis lead him to propound a great number of absurd pseudo-scientific theories.

Elizabeth Shandy (Mrs. Shandy)  -  Tristram's mother. Mrs. Shandy insists on having the midwife attend her labor rather than Dr. Slop, out of resentment at not being allowed to bear the child in London. On all other points, Mrs. Shandy is singularly passive and uncontentious, which makes her a dull conversational partner for her argumentative husband.

Captain Toby Shandy (Uncle Toby)  -  Tristram's uncle, and brother to Walter Shandy. After sustaining a groin-wound in battle, he retires to a life of obsessive attention to the history and science of military fortifications. His temperament is gentle and sentimental: Tristram tells us he wouldn't harm a fly.

Corporal Trim -  Manservant and sidekick to Uncle Toby. His real name is James Butler; he received the nickname "Trim" while in the military. Trim colludes with Captain Toby in his military shenanigans, but his own favorite hobby is advising people, especially if it allows him to make eloquent speeches.

Dr. Slop -  The local male midwife, who, at Walter's insistence, acts as a back-up at Tristram's birth. A "scientifick operator," Dr. Slop has written a book expressing his disdain for the practice of midwifery. He is interested in surgical instrument and medical advances, and prides himself on having invented a new pair of delivery forceps.

Parson Yorick -  The village parson, and a close friend of the Shandy family. Yorick is lighthearted and straight-talking; he detests gravity and pretension. As a witty and misunderstood clergyman, he has often been taken as a representation of the writer, Sterne, himself.

Susannah -  Chambermaid to Mrs. Shandy. She is present at Tristram's birth, complicit in his mis-christening, and partly to blame for his accidental circumcision by the fallen window shade.

Obadiah -  Servant to Walter Shandy.

Bobby Shandy  -  Tristram's older brother, who dies in London while away at school.

Widow Wadman  -  A neighbor who has marital designs on Captain Toby Shandy, and with whom he has a brief and abortive courtship.

Bridget -  Maidservant to Widow Wadman. Corporal Trim courts Bridget at the same time that Toby courts Widow Wadman, and Trim and Bridget's relationship continues for five years thereafter.

The midwife  -  The local delivery-nurse who is commissioned to assist at Mrs. Shandy's labor.

Eugenius -  Friend and advisor to Parson Yorick. His name means "well-born," and he is often the voice of discretion.

Didius -  A pedantic church lawyer, and the author of the midwife's license.

Kysarcius, Phutatorius, Triptolemus, and Gastripheres  -  Along with Didius, they form the colloquy of learned men whom Walter, Toby, and Parson Yorick consult about the possibility of changing Tristram's name.

The curate -  The local church official, also named Tristram, who misnames the baby when Susannah fails to pronounce the chosen name "Trismegistus."

Aunt Dinah -  Tristram's great aunt and, in Tristram's estimation, the only woman in the Shandy family with any character at all. She created a family scandal by marrying the coachman and having a child late in her life.

Lieutenant Le Fever  -  A favorite sentimental charity case of Uncle Toby's and Corporal Trim's. Le Fever died under their care, leaving an orphan son.