Edmund is the 23-year-old youngest son of the Tyrone family who has recently returned home after traveling at sea and working as a reporter. He suffers from a worsening respiratory illness that brings intense anxiety to the household. He has a philosophical, highly pessimistic outlook shaped by his reading of nihilist poets.

James is a 65-year-old former acting star who grew up in deep poverty. He commands the household with a deliberate, theatrical presence, but his extreme frugality frustrates his family constantly. He invests heavily in local real estate while aggressively cutting costs on his family's medical care and daily expenses.

Mary is the 54-year-old matriarch of the Tyrone family, recently returned home after a two-month stay away for health reasons. She suffers from painful rheumatism in her hands, entirely ending her youthful dreams of playing the piano. She feels deeply isolated in the family's summer home and remains highly anxious about her family's watchful, suspicious eyes.

Jamie is the 33-year-old eldest living son of the Tyrone family, possessing a deeply cynical worldview. He works reluctantly as an actor under his father's heavy influence and struggles with a well-known reputation for lacking ambition. He frequently acts as an instigator in family arguments but holds genuine affection for his younger brother.

Cathleen is the lively servant working in the Tyrone household during the summer. She actively observes the family's tense dynamics and often keeps Mary company when the men leave the house to run errands or drink. She speaks her mind plainly and readily enjoys a drink when offered by her employers.

Eugene is Mary and James's second child who died in infancy from an infectious illness. His tragic death years ago casts a long shadow over the entire family. He remains a lasting source of maternal grief and fuels Mary's complicated feelings toward her other sons.

Dr. Hardy is a local physician whom James trusts primarily because of his low fees. His medical assessments drive the family's anxiety regarding Edmund's declining health, but his professional competence is frequently questioned by the rest of the family.