Dame Jane Elizabeth Ailwên Phillips, known professionally as Siân Phillips, is a British actress from Gwaun-Cae-Gurwen, Glamorgan, Wales. Her early career consisted primarily of stage roles, including the title roles in Ibsen's Hedda Gabler and George Bernard Shaw's Saint Joan. In the 1960s, she started taking on more roles in television and film. She is particularly known for her performance as Livia in the 1976 BBC television series I, Claudius, for which she was awarded a BAFTA and a Royal Television Society award.

Gwaun-Cae-Gurwen is a village and community in Neath Port Talbot, South West Wales. Historically a part of Glamorgan, Gwaun-Cae-Gurwen is a parish made up of the electoral wards of Gwaun-Cae-Gurwen and Lower Brynamman.