He was born to a wealthy and extraordinarily eccentric family. As his father (Daniel Macnee), a race horse trainer, drank and gambled the family's money away, his mother (Dorothea Mary Henry) took young Patrick to live with her lover, Evelyn, in a huge mansion in southern England, where he wore kilts until the age of 11.
During his run on The Avengers (1961), Macnee's only weapon was an umbrella sword; he was rarely if ever seen carrying or using a gun. Macnee has stated in interviews that he insisted on this, because he had seen enough carnage in combat during his military service in World War II.
Was expelled from Eton for bookmaking.
Has played the role of Algernon Moncrieff in three different television productions of Oscar Wilde's "The Importance of Being Earnest".
Has two children from his first marriage to Barbara Douglas: Rupert Macnee and Jenny Macnee.