Biography
Jessie Royce Landis (born Jessie Medbury; November 25, 1896 – February 2, 1972) was an American actress. Her name is also seen as Jesse Royce-Landis. She remains perhaps best-known for her mother roles in the Hitchcock films To Catch a Thief (1955) and North by Northwest (1959). Description above from the Wikipedia article Jessie Royce Landis, licensed under CC-BY-SA, full list of contributors on Wikipedia.
Known For

The Swan
Princess Beatrix

Bon Voyage!
Countessa 'La Comtesse' DuFresne

Derelict
Helen Lorber

Boys' Night Out
Ethel Williams

North by Northwest
Clara Thornhill

My Man Godfrey
Angelica Bullock

Mr. and Mrs. Bo Jo Jones
Grandmother Greher

To Catch a Thief
Jessie Stevens

Meet Me Tonight
Olive Lloyd Ransome (segment "Ways and Means")

I Married a Woman
Mrs. Blake