She was diagnosed with glioblastoma multiforme about a month ago, and her health declined rapidly, her son Ryan Urich told CNN.
He said his mother died on Sunday, surrounded by loved ones at a family home in Canada.
Born in Toronto, Menzies-Urich's first screen credit came in the TV series 'The Farmer's Daughter' in 1964.
She was 15 when she was cast as the second-eldest daughter and third eldest of the seven von Trapp children in the Rodgers and Hammerstein musical 'The Sound of Music', a box office smash that won several Academy Awards.
Menzies Urich is survived by three children and eight grandchildren. (ANI)