Stanley is an out-of-work pianist in his late thirties who has been the only guest at Meg and Petey's seaside boarding house for a year. He rarely leaves the house, maintaining a slovenly appearance and an abrasive attitude, especially toward his landlady. Plagued by ambiguous anxieties, he relies on the routine of the house as a hiding place from the outside world, though he frequently claims he will soon leave to resume his music career.

Meg is a woman in her sixties who runs a run-down seaside boarding house with her husband, Petey. She constructs a rosy vision of her reality, insisting her establishment is well-regarded and on the verge of popularity. She craves attention and connection, directing intense affection toward her only boarder, Stanley, in a manner that inappropriately blurs the lines between mothering and romantic pursuit.

Nat Goldberg is a smooth-talking man in his fifties who arrives at the seaside boarding house under mysterious circumstances. He is highly verbose, frequently reminiscing about his youth and Jewish upbringing. Beneath his personable and gregarious exterior, he operates with an aggressive, manipulative focus, easily bending the other characters to his will.

McCann is an anxious, thirty-something Irish Catholic man assisting Goldberg with a vague assignment. He acts as the physical muscle of the duo, stepping in to block paths and physically intimidate others when commanded. Despite his threatening presence and willingness to bully, he frequently displays nervous energy and an underlying unease with his mission.

Petey is a man in his sixties who is married to Meg and co-owns the boarding house. He works outside the home and frequently attends a chess club, physically removing himself from the claustrophobic atmosphere of his own living room. Quiet and practical, he humors his wife's delusions and avoids direct conflict, simply telling her what she wants to hear.

Lulu is an attractive young woman in her twenties who lives near the boarding house. She brings an outside energy into the isolated home, attempting to coax Stanley into venturing outdoors and improving his grooming. Searching for affection and companionship, she eagerly responds to male attention when it is offered.