Howells was born in London, the daughter of composer Herbert Howells, and was educated at St Paul's Girls' School, where her father worked as Director of Music. She made her first stage appearance at Dundee in 1939, in John Drinkwater's Bird in Hand, then moved to Oxford in 1942 and three years later made her London debut at the Embassy Theatre, Swiss Cottage. In 1947 she appeared in the comedy Jane at the Aldwych Theatre. After several years in the West End, and a brief stint on Broadway where she appeared in Springtime for Henry in 1951, she began to appear in films.
After the death of her father in 1983, Ursula Howells instigated the "Herbert Howells Society" and became a standard bearer for the promotion of his work. She financially supported the recording of his compositions and did much to encourage the publishing and promotion of church music.
Lady Isabel Aubrey
Sarah Chandler
Miriam Wakefield
Elizabeth Fouchet
Laura Atherton
Janet Ormund
Duchess of Buckminster
Olive Nettleton
Mary
Miki
Mme Pontagnac
Barbara
Mary Winsloe
Julia Gray
Miss Blacklock
Empress Maria Fyodorovna
Miss Blacklock
Mrs. Deirdre Biddulph (segment 1 "Werewolf")
Barbara Mossman
Margaret
Adeline
The Duchess
Mrs Gradgrass
Miss Maxine Chambers (segment 3 "Mr. Steinway")
Mrs. Elliot / Mrs. Gilson
Maggi Thwaites
Mumsy
Ann
Headmistress
Lady Doughty
Mary
Estelle
Lucille Ainsworth
Antonia Pitt
Pam Vickers
Liz Essendine
Barbara
Peggy
Joanna Duten
Mary Dennis
Hon. Ursula
May Swift
Mme. Perrault
Mrs Fielding
Mrs Menant
Aunt May
Brenda Lucas
The Older Woman
Nurse Judith
Louise
Alice Andover
Liz Essendine
Eileen
Harriet Marshall
Barbara Karolina
Prue
Martha Tompkins
Pat Anstey
Emily