The Deep Blue Sea (1952) is a play by Terence Rattigan. In creating the play, Rattigan was inspired by the suicide of a young (male) actor with whom he had some time previously had a relationship. This has encouraged some commentators to speculate that the play is secretly about gay men.

This is not true; the play is undoubtedly animated by Rattigan's lifelong homosexuality, and his experience of hidden 'antisocial' passion, but he has written a very strong and vital part for a woman. Peggy Ashcroft, the first Hester, claimed to hate the part: 'I feel I'm walking around the stage naked'. Despite this, she had a major success with the role, and her comment serves to indicate how emotionally revealing, how unabashed, unrepressed this play is. It is probably the finest example of what 'well-made' playwriting could achieve.

The Deep Blue Sea begins with neighbours discovering the body of Hester Collyer who has tried and failed to commit suicide. Some time before she left her husband, a respectable High Court Judge, for a semi-alcoholic former airline pilot. The relationship was physical and passionate but his ardour has cooled, leaving her emotionally stranded and desperate. The aftershocks of her attempted suicide unravel even the remnants of this relationship, but by the end she is brought to a hard decision to live, partly through the intersession of another resident of the tenement house, Mr Miller, an ex-doctor, struck off for what seems to have been a homosexual offence. These two outcasts, socially ostracised for their 'excessive' loves, find a curious and moving kinship.