The Killing of Sister George is een Amerikaanse zwarte komediefilm uit geregisseerd door Robert Aldrich en gefilmd in zijn Aldrich Studios in Los Angeles. Het is gebaseerd op het toneelstuk uit 1964 van de Britse toneelschrijver Frank Marcus . In de film wordt een ouder wordende lesbische televisieactrice, June "George" Buckridge ( Beryl Reid , die haar rol uit het toneelstuk opnieuw vertolkt), tegelijkertijd geconfronteerd met het verlies van haar populaire televisierol en de ineenstorting van haar langdurige relatie met een jongere vrouw. ( Sunnah York ). Hoewel Marcus' toneelstuk een zwarte komedie was, werd de filmversie op de markt gebracht als een "schokkend drama"; het voegde expliciete lesbische inhoud toe die niet in het originele stuk was, en werd gepresenteerd als een serieuze behandeling van lesbianisme.
Middle-aged actress June Buckridge (Beryl Reid) plays "Sister George", a lovable motor scooter-riding district nurse and local sage, in a fictional long-running BBC television soap opera, Applehurst. She has been with the show for four years and is so identified with her character that she is nicknamed "George". Off-screen, June is outspoken, ribald, cigar-smoking and frequently inebriated, unlike her kindly on-screen persona. Although June has been popular with viewers in the past, several Applehurst characters have recently been killed off causing June to worry that Sister George may be next. Her worry affects her already volatile relationship with her live-in lover, a younger, beautiful woman named Alice (Susannah York), whom June calls "Childie". Childlike Alice plays with dolls, writes poetry, and has a minor fashion industry job, but relies on June for most of her financial and emotional support. Domineering June is alternately affectionate toward Alice and abusive to her, and reacts jealously when Alice spends time with other women or men. Alice rebels by talking back to June and refusing to play along with a "contrition" game in which June makes her kneel and eat a cigar butt.
After an Applehurst colleague jokes about Sister George possibly dying on the show, June walks out on a script reading, gets drunk, and forces herself into a taxi alongside two young Catholic nuns, whom she sexually assaults, resulting in the taxi having an accident in a busy intersection. The nuns' Mother Superior and the Archbishop complain to the BBC, causing powerful network producer Mrs Croft (Coral Browne) to visit June at home and lecture her about her behaviour and her attitude at work. When June balks at apologising for the incident, Mrs Croft makes clear that her future at the network depends on her apologising and changing her ways. Mrs Croft further infuriates June by taking an interest in Alice, complimenting her cooking and encouraging her poetic aspirations. At the next script reading, June finds that Sister George has been temporarily written out of the show with an illness, seemingly as punishment for June, and raising the possibility that her character will not recover.
June's spirits improve when she receives the next script, showing that Sister George has recovered and returned to riding her scooter. June and Alice go to a party at Gateways lesbian nightclub, to which she jokingly invites Mrs Croft. Halfway through the party, when June is already annoyed by Alice dancing with another woman, Mrs Croft arrives to tell June in person that Sister George will die by being hit by a ten-ton truck. After June storms off, Mrs Croft invites Alice to meet with her to further discuss Alice's poetry. On June's last day of filming for Applehurst, Alice untruthfully says she cannot meet June for lunch because she is busy at work. June, upset, tries to sabotage her fellow actors' performances and to drag out the filming as long as possible; afterward, she finds out that Alice lied to her in order to meet with Mrs Croft.
At her farewell cast party, June makes a scene, insulting the senior network executive, pouring drinks over a fellow cast member, and finally exploding in front of the guests when Mrs Croft offers her a new role as the voice of a talking cow on a children's puppet show. She confronts Mrs Croft and Alice, who leave the party together and return to June and Alice's flat. Mrs Croft persuades Alice to leave and stay with her for one night in order to avoid June's wrath, and offers to help Alice further her writing ambitions. Alice and Mrs Croft end up having sex in Alice's bedroom, and June catches them in the act; this leads to a final confrontation in which June reveals that Alice is thirty-two years old and the mother of a teenage daughter, whom she abandoned. Alice leaves with Mrs Croft, dropping her key in the letter box to show she will not return. Left alone, June wanders onto the deserted Applehurst set, destroying equipment and props and uttering "moo" like a cow.