Isobel Elsom (born Isabelle Reed; 16 March 1893 – 12 January 1981) was an English film, theatre, and television actress.

A Denver reviewer of the play wrote:If there is anybody in this man's town who doubts that Isobel Elsom, leading woman at the Elitch Gardens Theatre, is an actress of the highest rank, let that doubting Thomas see her work in The Outsider ... She not only is scoring a brilliant personal triumph, but is demonstrating to local playgoers exactly why she was one of the most popular actresses London ever knew!

Elsom's other screen credits included The White Cliffs of Dover (1944), The Unseen (1945), Of Human Bondage (1946), The Ghost and Mrs. Muir, Monsieur Verdoux, The Paradine Case, and The Two Mrs. Carrolls (all 1947), The Secret Garden (1949), Love Is a Many-Splendored Thing (1955), Lust for Life and 23 Paces to Baker Street (both 1956), and The Pleasure Seekers and My Fair Lady (both 1964).

Elsom's television credits included Armstrong Circle Theatre, Hallmark Hall of Fame, Lux Video Theatre, My Three Sons, Alfred Hitchcock Presents (at least four appearances), Playhouse 90, Hawaiian Eye, Straightaway, and Dr. Kildare.

Elsom died of heart failure at the Motion Picture & Television Hospital in Woodland Hills, California, aged 87.