She began her career in the theatre in 1911, and her first important success came on Broadway in 1912 when she created the role of Meg March in the original production of Marian de Forest's Little Women.

Her films include My Man Godfrey (1936), in which she plays the flighty mother of Carole Lombard's character, and In Old Chicago (1937) for which she won the Academy Award for Best Supporting Actress.

In 1960, Brady received a motion pictures star on the Hollywood Walk of Fame for her contributions to the film industry.

[5] Billed as Mary Rose, Brady debuted on stage in 1911 in New Haven in the operetta The Balkan Princess.

[4] She had the first major success of her career in 1912 when she created the role of Meg March in the original Broadway and national touring productions of Marian de Forest's Little Women; a play adapted from the novel by Louisa May Alcott.

[11] However, according to press at the time the film's director, Henry King, accepted on her behalf at the ceremony and friends of Ms. Brady delivered it to her home later that night.

In 2016, the Oscar historian Olivia Rutigliano noted that Miss Brady also followed this practice, which may have led to the story that the Academy was presenting her with a replacement trophy.