When Dolores Hart, 73, walks the red carpet at this year's Academy Awards as planned, no interviewer will need to ask who made her dress. She will be wearing her nun's habit from the Benedictine Abbey of Regina Laudis in Bethlehem, Conn., where she lives a life of contemplation and hospitality and is mother prioress.

Mother Dolores, as she is now known, is the subject this year of an Oscar-nominated documentary short, "God Is the Bigger Elvis," which airs April 5 on HBO. The documentary chronicles her life as a nun after a Hollywood career that saw her costar with Elvis Presley ("Loving You" in 1957 and "King Creole" in 1958), Anthony Quinn ("Wild Is the Wind," 1957) and George Hamilton ("Where the Boys Are," 1960). Her favorite is "Lisa," from 1962, in which she played a Jewish refugee after World War II. Before the documentary, she last appeared on the big screen in 1963's "Come Fly With Me," a comedy about flight attendants looking for love.

Not only does "God Is the Bigger Elvis" explore Mother Dolores' life in Hollywood and at the monastery, but it also chronicles the day-to-day life of the nuns at the abbey, which is also a working farm. Like Mother Dolores, a lot of the nuns had previous occupations, including the law and science, before they changed vocations.

The documentary's director, Rebecca Cammisa, whose own mother was a nun before leaving the convent after 10 years, is thrilled that Mother Dolores is going with her to the Academy Awards on Sunday. "This is her return to Hollywood after 50 years," said Cammisa. "This is her homecoming."

While an actress, Mother Dolores attended the Academy Awards three times, the last being April 9, 1962, at the Santa Monica Civic. As for her return after half a century, Mother Dolores said over the phone from the abbey that she was looking forward to seeing "the motion picture industry at work."

"I would like to see the academy at its best," she added. "I have such respect for the community, and they have given me a way of being a part of Hollywood within the monastic enclosure. So this will be a wonderful opportunity I certainly will never enjoy again in my lifetime."

Mother Dolores had been a devout Catholic before she joined the monastery — she converted to the faith when she was 10. While appearing on Broadway in 1959 in the comedy "The Pleasure of His Company," a friend told her to visit the tranquil monastery for some rest and contemplation. It was during this first visit that Mother Dolores felt a tug at her heart that maybe she should devote her life to God. But she was only 21 and the community's lady abbess felt she was too young to give up her career in Hollywood.

But four years later, Mother Dolores knew the time was right. "I think it was maturity," she said. "There was a realization I had gone through many more films and I had much more experience in Hollywood and more experience in life. I had come to understand more the implications of what was necessary. I think that eventually the realization of what needed to happen caught up with me. I was able to present to lady abbess a more mature character.

Leaving the film industry for her new vocation "was something I knew absolutely I must do even though I loved my career," she said.

"I really did. I had wanted it since I was 7 years, so I certainly wasn't leaving it because I didn't like or love it. It was just something I knew that God was asking."

She dropped her academy membership at the advice of the lady abbess, but it was reinstated in 1990 after the personal intervention of actor Karl Malden, the then-president of the Film Academy (and who had worked with her on "Come Fly With Me").

"They could send me films to be evaluated, which they couldn't do in the 1960s," she said. "He felt my opinion would be important to them. He felt to have an opinion of someone who had led a contemplative life would have significance. The lady abbess was completely convinced by him. I was reinstated. I had to pay my dues; we didn't want to take any privileges that weren't appropriate."

Mother Dolores said she isn't shocked by anything she sees in contemporary films. "We are a contemplative community but also a community that is based on hospitality," she said. "We receive visitors and meet visitors who need help. There isn't really too much in movies that we haven't seen on our doorstep. Hollywood reflects the problems in the society. I don't think Hollywood creates the problems."

And if the documentary wins, will she accompany director Cammisa onstage?

"I will do whatever they ask me to," Mother Dolores said with a soft laugh.

susan.king@latimes.com