Although she only made her MCU debut in 2019 with her solo movie Captain Marvel, Carol Danvers' origin story provided the character with a range of strong friendships, some of which are to be elaborated upon in future MCU projects.
Captain Marvel's onscreen connections to her fellow Avengers teammates have not been explored much at this point, but the comic books have given the iconic heroine long-running attachments to many of her contemporary heroes, whether they be purely friendships, romances, or mentor and mentee dynamics.
In The MCU
Maria Rambeau
Maria Rambeau was one of Carol's fellow pilots in the United States Air Force and her best friend during her initial life on Earth. Carol spent significant time with Maria and her daughter Monica outside of work, with the three becoming like a family.
Maria is crucial to the Captain Marvel story not only because she helped Carol to remember her early life, grounding the hero through their friendship, but also because it's established in WandaVision that she later founded S.W.O.R.D., an organization focused on extraterrestrial threats that seems born from Maria's experiences with the Kree and Skrulls.
Nick Fury
Carol Danvers is one of Nick Fury's most powerful allies in the MCU, and the pair's growing friendship during the events of Captain Marvel showed their shared dedication to protecting life on Earth while also demonstrating how Fury would later respond to similar alien threats.
Although the pair have not yet been seen together in the present-day MCU, Carol's connection to Fury was emphasized in her devastation at being told during Avengers: Endgame that he was a victim of the Blip. With Fury confirmed to appear in The Marvels, though, it looks like a reunion is a likely possibility.
Mar-Vell / Wendy Lawson
Kree scientist Mar-Vell, who adopted the name Wendy Lawson on Earth, was an inspiration, mentor, and friend to Carol Danvers in the Air Force, as she developed new aircraft to test and develop her top-secret Light-Speed Engine while giving Carol and Maria new chances to foster their skills.
In addition to playing Mar-Vell, actor Annette Bening also took on the role of the Supreme Intelligence, who assumed Mar-Vell's appearance in front of Carol in a move that unsettled and confused her while she was still suffering from amnesia. Given that the Supreme Intelligence is said to take on the visage of the person an individual most respects, Carol's ongoing admiration of Mar-Vell is clear to see.
Monica Rambeau
So far, the MCU onscreen interactions between Carol Danvers and Monica Rambeau have only occurred when the latter was a child. However, there's no denying that their bond is strong, with Monica considering Carol a part of her family, keeping objects of Carol's even when others said she'd disappeared in a plane crash.
The end of WandaVision, in which Monica appears as an adult, sees her meeting with a Skrull on behalf of Nick Fury regarding an intergalactic mission, leaving her poised for a reunion with Carol in The Marvels, and while there are many Monica Rambeau scenes from the comics fans are hoping to see in the movie, having the chance to fight as a superhero alongside Carol could let her fulfill a lifelong dream.
Talos
Carol's relationship with the Skrulls in Captain Marvel is a complex one, as illustrated by her at-first antagonistic relationship with Talos. But upon learning of the alien's plight with regards to his family, the two slowly become allies.
Talos' presence in the movie acts as an opportunity for Carol to uncover the lies the Kree have continually told her while also granting her the chance to confront her own prejudices as she learns more about Talos as an individual. This later leads to the pair working together not only to confront Yon-Rogg and the Starforce but leaving Earth on a mission to find a new habitable planet for Talos and his compatriots.
In The Comics
Jessica Drew / Spider-Woman
Arguably Carol's very best friend in Marvel comics is Jessica Drew, also known as Spider-Woman. The pair have always had one another's backs, whether they're teaming up in battle or hanging out in their downtime, with a history that stretches back to an Avengers comic from the 1980s (Avengers Annual #10).
They've been teammates in both the New Avengers and A-Force, but have consistently supported each other in their personal lives as well, whether it's in Carol helping out when Jess gives birth to her son, Jess helping Carol regain her lost memories, or being a sounding board for each other when it comes to making decisions in their superhero careers.
James "Rhodey" Rhodes / War Machine
Rhodey has been both a friend and love interest to Carol Danvers in the comics, with their romance being established in the run-up to the comic book event Civil War II, in which Rhodey's supposed demise set Carol against Tony.
As is often the case for Marvel heroes, though, Rhodey did not stay gone for long, and with his return, he and Carol resumed their relationship, one that lasted in the comics for several years. The pair have supported each other in their heroic endeavors, never wishing to hold the other back, and care for one another whether or not they are together romantically.
Kamala Khan / Ms. Marvel
A large part of Kamala Khan's origins as Ms. Marvel is tied up in her idolization of Captain Marvel, and once the two meet they share a fair number of adventures together, with Carol helping Kamala adjust to her superhero life, and Kamala soon leading teams of heroes on her own.
But with Civil War II featuring a strong Ms. Marvel comic storyline to read before the Disney+ series is released, came a complication to their mentor and mentee friendship, as they found themselves on opposite sides of the fight. Despite this, their years of friendship were impactful for them both, helping the heroes to feel confident under their respective titles as they entered new phases of their lives.
Peter Parker / Spider-Man
Though in the MCU Carol Danvers and Peter Parker are very different ages, their comics counterparts have a long history together, with some of the best Captain Marvel comic book stories coming about because of their team-ups.
Back in 2009, for example, when she still went by Ms. Marvel, Carol and Spidey were scheduled to go on a first date in a short-lived romantic storyline, but in a twist of events they end up interrupted by Mystique in an issue that showed how the lives of superheroes are forever complicated. Other team-ups since then have shown the friends taking on a number of other villains, and they always remain a charismatic team.
Jessica Jones
Jessica Jones became great friends with Carol Danvers when the latter was still using the Ms. Marvel title and was established as a recurring character in the critically acclaimed Jessica Jones comic series Alias, with the two ultimately teaming up to defeat Jessica's archenemy the Purple Man.
Although the pair aren't often shown interacting very much anymore, their friendship illuminated two very different spheres of the superhero world, from Jessica's street-level life as a private investigator to Carol's intergalactic missions. Despite these differences, though, the two always made time for one another and helped fight the other's personal battles.