Hollywood icon Doris Day, the popular movie actress and singer, has died at the age of 97.

Day, who was also an outspoken animal rights activist, died Monday in her home in Carmel, California.

"Day had been in excellent physical health for her age, until recently contracting a serious case of pneumonia, resulting in her death," The Doris Day Animal Foundation said in a statement.

Day's sunny, blonde, wholesome image became a staple of romantic farces in the 1950s and '60s. She often starred opposite Rock Hudson in films including "Pillow Talk" and "Send Me No Flowers," and also paired up with Cary Grant, James Garner, and Clark Gable.

She started her career as a singer, catapulting to fame with 1945's "Sentimental Journey," which became an anthem associated with troops returning from World War II. In the '50s, she became one of the most popular and bestselling singers in the country.

Day transitioned to movies, starring in musicals like 1953's "Calamity Jane." The film's song "Secret Love" won an Oscar and became Day's fourth No. 1 hit single in the U.S.

She broadened her roles beyond musical comedies and starred in Alfred Hitchcock's suspense thriller, "The Man Who Knew Too Much" in 1956. In that film, she sang "Que Sera, Sera (Whatever Will Be, Will Be)", which won an Academy Award.

As her film career began to wane, she headlined her own CBS sitcom, "The Doris Day Show," from 1968 to 1973. Day famously had to do the show because her third husband Martin Melcher had signed her up for it without telling her.

Day largely retired from acting following the show and focused on animal welfare activism. She received the Presidential Medal of Freedom in 2004 and a lifetime achievement Grammy in 2008. She also continued to make music, releasing the compilation album "My Heart" in 2011.

According to her foundation, Day wished to have no funeral, memorial service or grave marker. A list of survivors has not been released.