Romay died Dec. 17 of natural causes at Huntington Memorial Hospital in Pasadena, said her son, Jay Gould IV.
As Cugat popularized Latin music in North America, he made sure that he had "beautiful ladies who could sing fronting his band," including Romay — pronounced "Rome-eye" — "a warbler with surprising depth and range," Newsday reported in 1997.
Performing with Cugat for two years was so perfect, it "was like putting a glove on a hand," Romay told The Times in 1980.
Spotted onstage with Cugat's band at the Waldorf-Astoria Hotel in New York, she was soon signed to a seven-year contract with MGM about 1943.
Over the next decade, she made 15 films — and Hollywood made much of her Latin heritage.
Her father, Porfirio Romay, was a Mexican-born diplomat who had served in several Mexican consulates in the U.S., including in Los Angeles. Her mother, the former Lillian Walstead, was Irish and Norwegian.
A 1945 Times article began: "Lina Romay may be the songbird — and actress — to bring the Latin-American type to a new state of permanence in pictures."
Her films included "Bathing Beauty" (1944) with Esther Williams, "Adventure" (1945) with Clark Gable and "Love Laughs at Andy Hardy" (1946) with Mickey Rooney.
On a hayride in Brentwood, Romay met Jay Gould III, a great-grandson of the railroad baron. After they married in 1953, she stopped performing and raised three children in Bel-Air. Gould died in 1987.
In 1980, her performing career was resurrected when Hollywood Park hired her to provide horse-racing reports in Spanish to local radio stations.
"It's an exciting job," she said in 1980 in The Times, pointing out that she had "a flair for announcing these results."
She was born Maria Elena Romay on Jan. 16, 1919, in New York City.
As a recent high school graduate, she sang at a Pan-American event honoring her father, which led to a 15-minute weekly radio show in Detroit. When Cugat heard her on the radio, he arranged for an audition.
"She was the life of every party, the center of attention in everything she did," her son said. "Even late in life, she would sing in restaurants or at weddings. You just couldn't keep her down."
In 1992, she married Robert O'Brien, a writer for Lucille Ball's television shows. He died in 2005.
In addition to her son, Jay, Romay is survived by a daughter, Gloria Gould Gunter; and two grandchildren. A daughter, Anne, died in 1991.