LOS ANGELES — Doris Day, a leading box office star of the mid-20th century who achieved indelible fame in big-screen bedroom farces and put a sunny face on the working woman in postwar America, has died. She was 97.

The Doris Day Animal Foundation confirmed Day died early Monday at her Carmel Valley, Calif., home. The foundation said she was surrounded by close friends.

A former big-band singer and recording star who walked away from Hollywood in the early 1970s, Day had spent most of the last years in her beloved Carmel, where she was an outspoken animal rights activist.

When the light musicals she was originally known for began falling out of fashion in the late 1950s, she modernized herself by playing working women in romantic comedies.

With a bubbly screen presence and a blinding smile, Day effectively traded barbs with leading men and marched into the workplace in such lighthearted films as "Pillow Talk" (1959) and "Lover Come Back" (1961), two of the three films she made with Rock Hudson.

The transformation was box office gold. She received her only Academy Award nomination for "Pillow Talk."

"Her persona hit a cultural mother lode, tapping into what the average postwar woman was about," Drew Casper, a USC film professor, told The Times. She "was way ahead of her time, a feminist before there was feminism."

"Every female wanted to be Doris Day and every male wanted to marry somebody like her," Casper said.

From 1948 to 1968, Day appeared in 39 films, most often as the wholesome girl next door. At 46, she made her last film, "With Six You Get Eggroll."

Day's body of work shows "how much of an icon she was, how much she became in her own way, the female equivalent of John Wayne or Clint Eastwood," Times film critic Kenneth Turan once wrote.

In a 1976 essay in Ms. magazine, film critic Molly Haskell argued that Day was a proto-feminist who challenged "in her working-woman roles, the limited destiny of women to marry, live happily ever after and never be heard from again."

Not only was Day a rare movie heroine who worked, she had great jobs, playing an interior decorator in "Pillow Talk" and an advertising executive in "Lover Come Back."

"She conveyed a unique blend of innocent sexiness ... that was not so much the woman next door as the woman you wished lived next door," Times critic Charles Champlin wrote in 1988.