5 Actors Who Almost Played Supergirl Before Milly Alcock

When discussing major superhero roles, Supergirl remains a coveted part that's attracted a wealth of talent who have wanted to play the character throughout the years. Even though Milly Alcock's "Supergirl" bombed at the box office — much like Helen Slater's 1984 film decades earlier — don't expect actors to turn down the role of the Woman of Tomorrow when and if it becomes available.

As a matter of fact, when you look back at the people who have been linked with Kara Zor-El in the past, it's an impressive mix of TV favorites and renowned A-listers. Of course, not every rumor is true in showbiz, since a lot of publicists and agents push narratives around their clients to get them noticed. So, what we have done is find information from the sources themselves, or from those in the know, to discover who came close to playing Supergirl. This isn't just a list of names thrown up on Reddit for upvotes and downvotes, or provided by "trust me, bro" sources.

With that being said, let's explore the actors who almost played Supergirl before Milly Alcock. Let's just say that the prospect of a few of these names might have been fascinating to see onscreen.

If you're a fan of teen dramas from the 2010s, you need no introduction to Australian actor Claire Holt. She received attention for playing Samara Cook in "Pretty Little Liars" before venturing into the supernatural melodrama as Rebekah Mikaelson in "The Vampire Diaries." Holt would reprise the part of Rebekah in "The Originals" and "Legacies."

Considering the viewership of those shows also formed a part of the same demographic being targeted for 2015's "Supergirl" TV series, it should be no surprise to learn that Holt's name was thrown into a hat for the main role. But just how close was she to getting the gig? Top two — alongside Melissa Benoist, who would triumph in the auditions to be cast as Supergirl and join the Arrowverse timeline.

Appearing on 5 Things, Benoist revealed that Holt was her main rival for the part. "Really beautiful blonde girl," Benoist told host Jay Mewes. "She's awesome. She's great. And it was her and I, and I was, like, there's no way [I get it]." Holt would respond under the Instagram clip of Benoist speaking about her, writing, "You were the perfect Supergirl." If Holt had been cast, she would have been the first Australian to play Kara Zor-El in live action before Milly Alcock.

Before Milly Alcock was cast as Supergirl, there was another actor's name in the mix: Meg Donnelly. Much like Alcock, Donnelly was a rising star in the entertainment industry, having played Addison Wells in Disney's "Zombies" and Mary Winchester in "The Winchesters." However, Donnelly also had a special link to Supergirl, having voiced the DC character in the animated films "Legion of Super-Heroes" and "Justice League: Crisis on Infinite Earths."

As it turns out, it was Donnelly who put herself forward as a contender to play the Woman of Tomorrow on the big screen, too. "It was something that I really had to fight for to get an audition because I wanted to be a part of [it] and be Supergirl in any way," she told ComicBookMovie.com. "That was a dream of mine, to be a superhero on screen as well. So, I really fought for the audition, and the fact that I got one and they liked it, and I was then able to go and screen test."

Despite losing the role to Alcock, Donnelly refused to close the door on her live-action superhero ambitions. In the same interview, she expressed a willingness to play other characters in the DC Universe.

Christopher Reeve's Superman films changed the landscape of the comic book movie genre, as his version of the Man of Steel is a superhero performance that's practically flawless. Born out of this was a desire to spin out the universe and focus on Kal-El's equally powered Kryptonian cousin, Kara Zor-El, as the focal point of her own movie. Hence, the arrival of 1984's "Supergirl," featuring Helen Slater as the Maid of Steel.

However, Slater wasn't just the automatic pick for the part, as revealed by executive producer Ilya Salkind. "Helen Slater was totally unknown at the time, and when we tested her, we had seen a lot of girls, including Demi Moore, who turned it down," Salkind told SciFiNow. "But when we finally saw Helen, she absolutely stole the show, so we decided to go with her."

At the time, Moore wasn't as big a star as she would become later in the '90s, but she had attracted public attention by playing Jackie Templeton in the soap opera "General Hospital," so she would have been a much more recognizable actor than Slater in 1984. Would Moore have been a good choice as Supergirl, though? Well, we'll never know.

From Guinevere Beck in "You" to Vanessa Afton in the "Five Nights at Freddy's" franchise and Quinn Powers in "Elsbeth," Elizabeth Lail continues to rack up formidable credits on IMDb and become an in-demand actor in the business. One illustrious role eluded her in the early stages of her career, though: Supergirl.

Before Melissa Benoist soared up in the sky as Kara Danvers in the superhero series, Lail was one of the people who tested for the part. Ultimately, it wasn't meant to be, but her career didn't suffer from the setback. Not at all. In fact, the failed audition had the opposite effect, as she was cast in notable movies and TV shows afterward.

Speaking to The Hollywood Reporter, Lail revealed that she never tried on the famous Supergirl costume, but she acted out other scenes that formed a part of the series (with Benoist replacing Lail as the lead, of course). "We did stuff between Kara and her sister if I remember correctly," Lail said. "We did the human interactions in the pilot when she hadn't quite become the superhero that I'm sure she is now. That was so much fun for me. I loved doing that test."

Hollywood works in mysterious ways. Sometimes, actors walk in for one part but leave with another. Just ask Nicholas Hoult, who played Lex Luthor in James Gunn's "Superman," even though he auditioned for the part of the Last Son of Krypton first. As it so happens, "West Side Story" star Rachel Zegler went through something similar when she read for the part of Supergirl in 2023's "The Flash" — a role that went to Sasha Calle in the end.

"I read for Rich [Delia], who was our casting director, and he originally had come to me with Supergirl for "[The] Flash," and I was not right for it," Zegler told /Film. "He was like, 'You know what, I've got a character in mind for you for 'Shazam.' They're looking at X, Y, Z. We would love it if you came in and read.'"

It turned out okay for Zegler, as she was cast as Ann/Anthea in "Shazam! Fury of the Gods," which was a pivotal role in the movie. Having said that, it would have been interesting to see what Zegler might have done with the part of Supergirl in "The Flash," and if the fate of the role would have also ended as a one-and-done deal, the same way as it did for Calle.