Some actresses arrive as fully formed grown ups, even when they are still well within the age range of ingénues. Susan Sarandon is one of them. From her earliest roles, she brought to the screen a strong, distinctive presence and versatility few of her contemporaries could match. Since then, she’s proven she can do it all — and that “all” includes courage, wit, moxie, determination, warmth, sexiness, and fierce intelligence. 

Surreal elements may spin around Sarandon  like transvestite scientists (“Rocky Horror Picture Show”), Egyptian vampires (“The Hunger”), or Satanic seduction (“The Witches of Eastwick”)  yet she is the bedrock that makes it all seem possible; she will be the human element that makes us care. If Sarandon is an anchor, she is the most thrilling and watchable anchor we know, and the moment she enters the frame we find our emotional mooring.

Born Susan Tomalin in Queens, New York, in 1946, the future Susan Sarandon was raised in a large Roman Catholic family. (How large? Susan is the oldest of nine children!) Starting out in soap operas, Sarandon got the prototypical big break when, along with first husband, Chris Sarandon, she auditioned for John Avildsen’s hippie vigilante movie (now there’s a genre!), “Joe” (1970). Chris did not make the movie, but Susan did, and she leapt from the small screen to the big without breaking stride — and has barely slowed down since.

The Sarandon canon is packed with smart, gutsy performances, as her five Academy Award nominations attest, but the roles that distill the essence of her enduring appeal pay off like a trifecta of mature, complex women. In “Bull Durham” (1988), surely the most quotable role for an eternally quotable Sarandon, the sass and savvy of her Annie Savoy controls not just a baseball team, but also, it seems, the entire sport.

The sexual tension squares off between Sarandon and Triple A veteran catcher Crash Davis, played by a ground-pawing Kevin Costner, but in real life, it was actor Tim Robbins, in the role of rookie pitcher-savant “Nuke” LaLoosh, who walked off with the leading lady. (After 23 years together, the couple parted ways in 2009.)

As Louise, the best of all best friends, in 1991’s “Thelma and Louise,” Sarandon literally drives the movie into a place in film history, while simultaneously creating a template for the modern female outlaw. The role grabbed an Oscar nomination for Sarandon and a spot on the cover of Time Magazine for co-stars Sarandon and Geena Davis.

And in something of a homecoming for lapsed Catholic Sarandon, who once said, “I was told I had an abundance of original sin,” her work as real-life, anti-death penalty crusader Sister Helen Prejean in “Dead Man Walking” (1995) seared onto celluloid her fearlessness and indelible humanity. “Dead Man” was so much more than just a part, as the movie was made at the behest of Sarandon and Robbins, who convinced Sister Helen to take her appeal against capital punishment to Hollywood. The result: Best Actress and Actor Oscars for Sarandon and co-star Sean Penn. (Ironically, in 2010’s “You Don’t Know Jack,” Sarandon plays right-to-die activist, Janet Good, opposite Al Pacino’s Jack Kervorkian.)

Far from a career capper, the Oscar served as the shift into a higher gear that shows no signs of downshifting. Challenging the conventional wisdom that limits the prospects for actresses over forty (or fifty, or sixty), Sarandon is as youthful now (she actually turns 68 tomorrow) as she was mature in her twenties. This is what it means to be truly ageless. This is why we will never take our eyes off her.

Happy Birthday, Susan Sarandon.