Big studio executives have huge decisions to make when they cast their superhero movies, because these actors could be playing their characters for years to come. This means that they have to pick people that not only look the part but they also have to be really good actors. On top of that, they have to be really attractive and bankable because the studios want to fill seats in the theaters. Their actors have to look the part and be in really good shape. Once they've cast their incredibly good looking main cast of characters, they still have to cast all the supporting roles in their superhero flick.

Astonishingly enough, some of these supporting actors, some of who have a pretty small role, are actually much more attractive than the main cast of characters. In fact, you might even have forgotten that some of these actors played a role in some of your favorite superhero movies because their role was so brief. Let's take a look at 15 actors who played a small but important role in our favorite superhero movies -- important because they were so hot that they practically lit the screen on fire every time they were on it.

15 KATE MARA - IRON MAN 2

Kate Mara had a starring role in the horrendous Fantastic Four reboot, but that's not what we're talking about today. We're talking about her blink and you missed it appearance in Iron Man 2 where she played "U.S. Marshall". That's right. Her character didn't even have a name -- just a job title. Given her prolific filmography today, starring in House of CardsAmerican Horror Story and The Martian, it is quite surprising that the accomplished actress had such a tiny role.

In any case, if you forgot her appearance, here's what happened. She served Tony Stark a subpoena as he was leaving the Stark Expo. She literally has three lines. That's it. That doesn't stop her from being incredibly beautiful and it doesn't stop you from hitting pause while watching the movie.

14 COBIE SMULDERS - AVENGERS

Cobie Smulders as Maria Hill with a scar on her cheek in Avengers.

The beautiful Canadian actress most known for her role as Robin in How I Met Your Mother has made brief appearances throughout the MCU most notably in the Avengers films and Captain America: The Winter Soldier where she played Maria Hill, the Deputy Director of S.H.I.E.L.D. and later working with Stark Industries.

In a world filled with superheroes, any human that isn't Nick Fury or a love interest is bound to be sidelined, especially since the number of heroes has been growing exponentially. She is rumored to make an appearance in Avengers: Infinity Wars but it has yet to be confirmed. Even if she doesn't appear in that movie, you can always watch her on reruns of How I Met Your Mother if you need your Smulders fix.

13 IDRIS ELBA - THOR

idris elba in thor: ragnarok

Idris Elba is an incredibly handsome and tall London-born actor who has appeared in all of the Thor films as well as a brief appearance in Avengers: Age of Ultron as Heimdall, the all-knowing guard of the Bifrost Bridge. The charismatic actor is given little to work with as he spends most of the films standing around and protecting the bridge.

When he is given an action scene, it is short-lived. Elba is so dashing that he has been a fan favorite to play James Bond after Daniel Craig retires from the role for some time now. Although we still have no idea who will replace Craig for the time being, everyone would be very happy if Elba were chosen, because he would be perfect for the role.

12 OLIVIA MUNN - X-MEN: APOCALYPSE

Although Olivia Munn made a tiny cameo appearance in Iron Man 2 as Chess Roberts, a reporter tasked with providing exposition for the film with regards to the Stark Expo, we are going to focus on her role in X-Men: Apocalypse. In the film, she played Psylocke, who was recruited by Apocalypse as one of his horsemen. The beautiful actress' role in the film was infuriating, because her character had absolutely no agency.

We learn nothing about her and we have no idea why she chose to join Apocalypse on his quest to rule the world. She is supposed to return to the franchise in X-Men: Dark Phoenix, and we hope for her sake that she is given a little more to work with. She's much more than a pretty face.

11 EVANGELINE LILLY - ANT-MAN

Although Evangeline Lilly of Lost and The Hobbit Trilogy fame had a somewhat prominent role in Ant-Man, it wasn't what fans had expected. She played Hope van Dyne, daughter of Hank Pym, the revolutionary scientist who was able to invent a shrinking suit. The reason fans were confused by van Dyne's appearance in the film was because she was a much more experienced fighter than Paul Rudd's Scott Lang, and she would have been a better choice to don the Ant-Man suit.

The film chalks it up to the fact that Pym didn't want to lose his daughter the way he lost his wife so he would rather trust an ex-con with his technology than his daughter. Still, at least we will see her don the Wasp suit in the sequels. Also, did we mention Lilly is gorgeous?

10 TAO OKAMOTO - BATMAN V SUPERMAN

Tao Okamoto is a 5'9 actress and model who is 32 years old. She was born in Japan and eventually moved to New York City to pursue her career. As a model, she has walked the catwalk for a number of different designers such as Chanel, Ralph Lauren and Yves Saint Laurent. Okamoto made her feature film debut in The Wolverine as Mariko Yashida, granddaughter of Ichirō Yashida and heir of his tech company.

She had a rather sizable role in that film, but she had an absolutely tiny role in Batman v Superman: Dawn of Justice where she played Mercy Graves, Lex Luthor's assistant. Graves barely utters a word in the film before she is killed off, which is a huge shame because the actress as well as the character had a lot of potential.

9 GWYNETH PALTROW - IRON MAN

Gwyneth Paltrow Iron Man Bad On-Set Behavior

You could argue that Gwyneth Paltrow had a substantial role in the Iron Man movies, but as of late, she all but disappeared from the MCU lineup. In fact, for someone whose charisma and rapport with Robert Downey Jr. helped kickstart the MCU, it is surprising we haven't seen much of her since Iron Man 3, apart from a short cameo in Spider-Man: Homecoming.

She is slated to appear in Avengers: Infinity War, but we can't imagine she will have much screen time given the number of characters there are in the film. In any case, the 45-year-old actress and health nut is as gorgeous as ever and hasn't aged in years. We certainly hope to see more of her in the MCU in the future.

8 REBECCA HALL - IRON MAN 3

Maya-Hansen-Rebecca-Hall

The beautiful London-born actress played Maya Hansen in Iron Man 3, a biological botanist and former fling of Tony Stark. She helped Aldrich Killian design the Extremis Virus which cured Killian of his physical handicaps -- it also happened to give him the ability to heal himself, breathe fire and turn him into a crazy supervillain.

It is quite clear that Hall will not return to the MCU, since we doubt her character can serve any purpose within the series at this point. That doesn't take away from the fact that she is extremely attractive and is certainly up there in the looks department with all of the MCU A-listers. Hall has been keeping busy with a slate filled with a lot of different film and TV projects.

7 CLAUDIA KIM - AVENGERS: AGE OF ULTRON

Claudia Kim started out her career by winning a modeling contest. The tall and stunning South Korean actress played Dr. Helen Cho in Avengers: Age of Ultron. Her character suffered the same fate as Hawkeye in the first Avengers film: she was mind-controlled for a good portion of the movie and didn't have much to do with the role. Although it appears that she is done working in the MCU for now, she has other film work keeping her busy like The Dark Tower and Equals. 

Later this year, she will star in Fantastic Beasts: The Crimes of Grindelwald as Maledictus, which is the next installment in the Harry Potter prequel trilogy. It doesn't appear as though she has anything else in the works for the time being but we hope to see more of this stunning woman in the future.

6 COREY STOLL - ANT-MAN

Corey Stoll, who made a name for himself in Hollywood for playing Peter Russo in House of Cards and Hernest Hemingway in Midnight in Paris, saw his star-0-meter shoot to the sky when he appeared in a Marvel Cinematic Universe movie. The tall, charming actor was cast in the MCU's Ant-Man film as Darren Cross, aka Yellowjacket. As everyone expected, this would once again be a case of a great actor being underutilized for a lame villain role that everyone would forget.

He plays a former former protégé of Hank Pym who later takes over Pym Technologies. He ends up having a boring evil plot to sell his shrinking technology to Hydra. As silly as his character is, Stoll is a great looking guy who always looks sharp in a suit.

5 JAIMIE ALEXANDER - THOR

The 15 Most Gorgeous Celebrity Geeks

When Jaimie Alexander first graced the big screen in Thor, chances are it was the first time most Marvel fans had ever seen the actress. And chances are that as soon as they saw her, they gasped, "Who's that?" That's because Jaimie Alexander, who played Lady Sif in the first two Thor movies as well as a couple of episodes of Agents of S.H.I.E.L.D., is breathtakingly beautiful.

Unfortunately we doubt she will play much of a role in any MCU film to come. Do you want to know when you no longer matter as a superhero in the MCU? When you make an appearance on Agents of S.H.I.E.L.D. Luckily, Alexander is doing just fine as she has been getting steady work on her show Blindspot.

4 ANTJE TRAUE - MAN OF STEEL

Antje Traue is a German actress who got her first English-speaking role in the 2009 film Pandorum opposite Dennis Quaid and Ben Foster. She was later cast as Faora, one of General Zod's trusted goons in Man of Steel. You would have no way of guessing it given her tough as nails performance in Man of Steel, but Traue is only a hair over 5'5 which is a lot shorter than we would have guessed.

The beautiful actress had a pretty small role in the film, but she continues to work in Hollywood. She has been in Woman in Gold and Criminal. Most recently, she has appeared in a few episodes in the Netflix series Dark, which tells the story of the disappearance of two children and the ramifications it has on different families in the German town.

3 LINDA CARDELLINI - AVENGERS: AGE OF ULTRON

linda cardellini

Linda Cardellini, who has had a long career in drama and comedy that includes notable performances in Freaks and GeeksERScooby-Doo films and TV shows and Mad Men, was cast in Avengers: Age of Ultron as Laura Barton. The veil was finally lifted around the mystery that was Hawkeye and audiences finally got a look at Clint Barton's home life.

They were surprised to discover that Barton not only have a stunning wife, but children as well. Cardellini is simply ageless and she's an extremely gifted actress with great comedic timing and although her role was brief, she will reprise it in Infinity War. However, given the fact that the film features more characters than we can count, we doubt she will have much screen time.

2 LANA CONDOR - X-MEN: APOCALYPSE

Lana Condor Feature

Lana Condor who will soon be seen on the big screen portraying Koyomi in Robert Rodriguez' Alita: Battle Angel got her first starring role in Bryan Singer's X-Men universe in the film X-Men: Apocalypse. In the film, she played Jubilee, a fan favorite among X-Men fanboys, who has never gotten much screen time in the films. Although Jubilee gets more screen time than ever in Apocalypse, it still wasn't enough to satisfy fans.

Neither Condor nor Fox have confirmed whether or not Jubilee will be back for the next X-Men film X-Men: Dark Phoenix, but fans certainly hope to see more of her in the future, especially since a lot of her scenes were cut in Apocalypse. Condor was born in Vietnam and adopted by Americans and moved to the States. Apart from acting, she has also studied ballet.

1 JENNIFER CONNELLY - SPIDER-MAN: HOMECOMING

Many of you might have read the title of this list entry and questioned your sanity. You don't remember seeing Jennifer Connelly in Spider-Man: Homecoming. Well technically, you were right. We didn't actually see her in any scenes of the film, but we did hear her. Connelly played Karen/Suit Lady, the A.I. present in the Spider-Man's upgraded suit after he manages to remove the training wheels mode with the help of his friend Ned.

It is quite curious that they gave such a gorgeous actress a role where we can't even see her, but it is interesting to point out that her husband Paul Bettany started out as Tony Stark's A.I. before turning into Vision. Perhaps Connelly's character will get the same treatment at some point.