Spoiler warning: This article contains spoilers for Doctor Strange in the Multiverse of Madness.
Doctor Strange in the Multiverse of Madness brought Captain Carter into live-action for the first time. The movie also killed her off in a brutal fashion at the hands of the Scarlet Witch. Captain Carter fans know this isn't the end, though. The Earth-838 version died in the movie, but the What If..? version survives and Captain Carter could appear again in live-action elsewhere in the MCU.
Captain Carter likely appears in the MCU again as the multiverse expands into other movies and shows. Variants of her exist throughout the comics, including a new one based largely on Hayley Atwell's new take on the character. If the MCU adapts the 2015 Secret Wars storyline that brings together the multiverse into Battleworld, she stands a great chance of appearing alongside myriad Marvel heroes and villains.
Loki Season 2
The multiverse means everything in Loki, and season 2 promises to visit even more branch timelines. Captain Carter stands a chance of appearing in them and she may have already actually made her first live-action appearance in Loki season 1.
When Loki first arrives at the Time Variance Authority, he sees a woman who looks a lot like Peggy Carter being taken away. If this proves to be the case, this variant of Peggy or Captain Carter could play a role in helping Loki deal with the growing threat of Kang the Conqueror.
What If..? Season 2
Producers confirmed that Captain Carter returns in What If..? season 2, picking up on the narrative threads from the season 1 finale. Next season, she likely confronts the fact that her universe's Winter Soldier is Steve Rogers.
This version of Peggy serves as the lynchpin of the animated series in many ways after kicking off the story and recurring in several episodes. Comic book fans know Uatu the Watcher sees all, and her connection to him allows for the possibility they both make it into live-action.
Captain America 4
Captain Carter ranks as one of the most important versions of Captain America. She possibly appears alongside another in Captain America 4. The story of the upcoming movie remains unknown, except Sam Wilson features in the title role.
If the movie connects to the macro multiverse story arc, then Captain Carter could make her next MCU appearance in the movie. Fans loved seeing all the different Spider-Men together and it would be great to see all the MCU Captain Americas in a big team-up.
Ant-Man And The Wasp: Quantummania
Ant-Man and the Wasp: Quantumania features Kang the Conqueror as the villain, and that raises the possibility of Captain Carter appearing. This variant of He Who Remains from Loki likely makes his first major move in the MCU in this movie.
Ant-Man and The Wasp likely travel through the Quantum Realm to other realities in the movies, and Captain Carter may appear in some form. Either the possible Loki variant appears, or perhaps another iteration of Peggy from the multiverse could.
Fantastic Four
The Fantastic Four movie remains one of the most anticipated future MCU movies. With the appearance of John Krasinski as Reed Richards alongside Captain Carter in Doctor Strange in the Multiverse of Madness, a chance exists she appears in the FF movie.
The Earth-838 version of Captain Carter died fighting the Scarlet Witch, so this would be a new variant. Perhaps Reed Richards and Captain Carter serve on other versions of the Illuminati throughout the multiverse. Doctor Strange in the Multiverse of Madness made clear the Earth-838 version presided only over their universe, and didn't oversee other timelines as the Time Variance Authority does.
Scarlet Witch Movie
The Scarlet Witch appears to die at the end of Doctor Strange in the Multiverse of Madness, but her MCU story is likely far from over. Wanda's significance in the MCU only grows with every appearance and she could be the focus of a movie in the future. Captain Carter's next MCU appearance makes sense here given Wanda's actions against the Illuminati.
Wanda proved once and for all her status as one of the most powerful magical beings in the Marvel Universe but she may need to find a way to atone for her actions. She could seek to undo what she did to Captain Carter and the other Illuminati in Earth-838 or try to help variants of them elsewhere in the multiverse.
Doctor Strange 3
Doctor Strange in the Multiverse of Madness tells fans a lot about the future of the MCU. The Sorcerer Supreme continues his journey through different realities and dimensions at the end of the movie and that could lead him back to Captain Carter.
In the mid-credits scene, Clea arrives to tell Doctor Strange he created an incursion. She then takes him to the Dark Dimension, just one of infinite realms in the multiverse. This development likely continues the multiverse thread in the MCU in a way that links back to Captain Carter and possibly even more variants.
Secret Wars
The concept of incursions stems from the 2015 Secret Wars storyline, one of the best Marvel Comics events. In the comic, incursions ultimately destroy all the universes in the multiverse until one remains, an amalgamation called Battleworld.
Captain Carter appears in some form in an MCU version of this storyline, as it brings together the significant variants of virtually every Marvel Comics superhero and villain. Events in the MCU hint that this is the direction the franchise is going.
Captain Carter Movie
Though the Earth-616 Peggy Carter found her happy ending with Steve Rogers, and the Earth-838 version died tragically, it's clear the MCU isn't done with Captain Carter. A Captain Carter movie makes sense as her next MCU appearance, and the What If..? producers have already called for it, as reported by The Hollywood Reporter.
What If..? revisits Captain Carter from time to time, but many story possibilities exist for the character. A live-action version of that character or another variant allows the MCU to fully explore the potential of the powerful and compelling superhero.