Aileen Sibell Mary Plunket (née Guinness; 1904–1999) was an Anglo-Irish society hostess.

[1] In 1923, she and her sisters were sent on a world tour in her father's high masted yacht, Fantome II.

When she married Brinsley Sheridan Plunket, her father bought her Luttrellstown Castle near Dublin.

[2] Over the next 50 years, Plunket redesigned the interiors of Luttrellstown Castle using the service of Felix Harbord.

He was extravagant and Plunket's lifestyle had to be trimmed after her father died and death duties had to be paid.