In this Jan. 28, 1989 file photo, actress and animal rights activist Doris Day poses for photos after receiving the Cecil B. DeMille Award. (AP Photo, File)

Hollywood legend Doris Day - whose career spanned over 80 years - has passed away just a month after turning 97, her animal welfare foundation, announced on Monday.

Doris began her career as a singer, with her breakthrough hit 'Sentimental Journey' being re-recorded several times over her career, and she became one of the highest-paid vocalists in the US in the 1950s.

She moved into movies with the lead role in 'Romance on the High Seas' in 1948 and went on to star in hits such as 'I'll See You in My Dreams', 'Calamity Jane', 'Love Me and Leave Me' and 'The Man Who Knew Too Much', the latter of which led to her Academy Award win for Best Original Song thanks to 'Que Sera, Sera (Whatever Will Be, Will Be)' and later became the theme tune for 'The Doris Day Show', which ran for five years from 1968 to 1973.

Following a long absence from the spotlight, Doris released her album 'My Heart' in 2011, her first new record in almost two decades.

Two years ago, Doris discovered she was actually two years older than she had previously thought, when a copy of her birth certificate, obtained from Ohio's Office of Vital Statistics, revealed the actress was actually born in 1922, and not 1924 as she'd once believed.

In a statement at the time, she said: "I've always said that age is just a number and I have never paid much attention to birthdays, but it's great to finally know how old I really am."

The documentation showed that the actress was given her pre-fame name of Doris Mary Ann Kappelhoff on 3 April 1922 by her parents Alma and William Kappelhoff of Cincinnati.

Doris married four times and had a son, Terrence, with her first spouse Al Jorden, who was later adopted by her third husband, the late Martin Melcher, but he died in 2004.