Jeans was born in Simla, British India, to English parents, and brought up and educated in London.^[3] She was the youngest of three siblings. Her brother Desmond Jeans was a boxer and actor, and her elder sister, Isabel, was also an actress.^[4] In 1931 she appeared in Edward Knoblock's Grand Hotel at the Adelphi Theatre.

Jeans made her stage debut in London in 1922,^[5] before joining the cast of the London production of The Play's the Thing, an adaptation of Ferenc Molnár's play, The Play at the Castle by P. G. Wodehouse.^[6] The cast included Gerald du Maurier, Ralph Nairn, Henry Daniell (before he went to Hollywood), and Henry Forbes-Robertson.^[7]

She made her stage debut in New York in 1933.^[8] Her first marriage was to actor Robin Irvine (1931–1933, his death). Her second marriage was to actor Roger Livesey from 1937 until her death.^[9] (Livesey's sister Maggie was already married to Desmond Jeans.) She appeared in one film with Livesey, The Life and Death of Colonel Blimp (1943).^[10] She entertained troops with ENSA during World War II, sometimes working with her husband. They appeared on stage together in Watch on the Rhine, Ever Since Paradise and Uncertain Joy. After the war, she continued acting, including starring as Mrs. Tarlton, in one of the eight episodes of the BBC's 'H M Tennant's Globe Theatre', in 1956; and, in a stage tour of Australia and New Zealand, between 1956 and 1958.

Jeans made one appearance each in Dixon of Dock Green, in 1967, as Mrs. Regan; in Theatre 625, as Mother Denis, in 1968; and as Ursula Benton, in The Root of All Evil?, also in 1968. She continued to act into the 1970s.

Jeans died of cancer in 1973, aged 66, some 18 months after her diagnosis.^[9] She shares a memorial plaque with her second husband, Roger Livesey, in the actors' church St Paul's, Covent Garden.

• Ursula Jeans at IMDb
• Ursula Jeans at the Internet Broadway Database
• Performances listed on the Theatre Archive University of Bristol