Decades after her acting and singing careers came to an end, Brigitte Bardot is today primarily known for her animal-rights activism and for her frequent scrapes with the French authorities over her passionate, public denunciations of what she considers the "Islamification" of her native France. (She has been fined five times for "inciting racial hatred" in books and speeches, arguing in 2003, for example, that France has "given in to a subterranean, dangerous and uncontrolled infiltration which not only resists adjusting to our laws and customs but which will, as the years pass, attempt to impose its own.")
All these years later, however, it's still difficult for anyone who was not alive at the time to grasp the galvanizing effect that Bardot had—as an actress and as a sex symbol—on moviegoers around the world in the 1950s and early 1960s. Here, on her 80th birthday (she was born Sept. 28, 1934, in Paris), LIFE.com celebrates the young Bardot with a series of pictures—most of which never ran in LIFE—made by Loomis Dean in 1958.
In a June 1958 article titled "The Charged Charms of Brigitte," LIFE waxed lyrical (and, to contemporary ears, a touch patronizing, if not downright sexist) about the 24-year-old actress' effect on American moviegoers and critics:
Not since the Statue of Liberty has a French girl lit such fires in America, and Brigitte Bardot does not just stand there like a statue. She moves, she wriggles, and her clothes are as often off as on. One of her films, "And God Created Woman," has played for eight solid months in one New York theater and raked in some $2 million in the U.S. and, with her four other current films, has jammed art theaters until people complain they are clogging up culture. What Bardot has—which is more than sex—still mystifies many who stop to think about it . . . Meanwhile, the Bardot boom balloons. With four new films to open before years' end, she's finishing a fifth, "The Lady and the Puppet" ["La Femme et le Pantin," but often billed simply as "The Female" for the English-speaking world], made in Spain where these pictures were taken.
In gaining her present eminence, Brigitte Bardot has had certain advantages beyond those she was born with. Like the European sports car, she has arrived on the American scene at a time when the American public is ready, even hungry, for something racier and more realistic than the familiar domestic product. Americana actresses, like American four-door sedans, seem to have grown more and more standardized in styling.
No Hollywood girl can play a mechanic's wife or even an early western rancher's daughter without being made up as precisely as the Marquise de Pompadour and garbed like a Main Line heiress. By contrast, an actress who lets her hair get in her eyes, who looks as though she could perspire at least lightly and who wriggles greedily as she kisses a man comes as a revelation.
But none of this really explains why Brigitte Bardot has been so successful. Other foreign actresses have had the same opportunity to profit from public receptiveness and the lack of censorship but none of them has been able to match her accomplishments. Brigitte, also known as B.B. and the Sex Kitten, has not lifted a finger to achieve publicity. In fact, she treats all reporters like net men from the city pound. . . . The male viewer, having been frankly invited to admire the lush Bardot charms, is soon forced to an uneasy suspicion that he is a wicked old man.
And on it goes—an endless stream of metaphors (she's a car, or a kitten, or perhaps some primeval erotic force merely visiting Earth in the guise of a twenty-something French beauty) that remind us of why, in part, Bardot left acting behind when she was not yet 40 years old. She had helped to create and to define the sex-goddess archetype in the movies, but found herself almost entirely unable to break out of that mold no matter how "serious" her roles became or how nuanced her performances actually were.
In the end, then, if nothing else, the pictures in this gallery help explain why most critics and most audiences were, perhaps, unable to see beyond the sheer sensuality that Brigitte Bardot exuded, both onscreen and off. Ater all, for a while there in the middle part of the last century, she might just have been the sexiest woman on earth.
Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter at @LizabethRonk.