Katharine Macmillan, Viscountess Macmillan of Ovenden

Katharine Macmillan, Viscountess Macmillan of Ovenden, DBE (born as The Honourable Katharine Margaret Alice Ormsby-Gore on 4 January 1921) is the daughter of the 4th Baron Harlech and granddaughter of the 4th Marquess of Salisbury.

On 22 August 1942, she married Conservative politician Maurice Macmillan. They had five children together:
* 1) Alexander Daniel Alan Macmillan, 2nd Earl of Stockton (born 1943)
* 2) The Honourable Joshua Edward Andrew Macmillan (1945-1965)
* 3) The Honourable Adam Julian Robert Macmillan (born 1948)
* 4) The Honourable Rachel Mary Georgia Macmillan (1955-1987)
* 5) The Honourable David Maurice Benjamin Macmillan (born 1957)

She was Vice-Chairman of the Conservative Party in 1968 and was created a Dame Commander of the British Empire (DBE) in 1974. She became Viscountess Macmillan of Ovenden in February 1984 when her father-in-law, former British prime minister Harold Macmillan, accepted a peerage and was created Earl of Stockton. Her husband died the following month, so never inherited the earldom from his father.