Warning: The following contains spoilers for Hawkeye on Disney+.
Even though he goes up against aliens with a bow and arrow, Clint Barton is a practical guy. He wouldn't spend much time focused on his horoscope, or wondering which of his friends had which zodiac sign. Just knowing that, astrology fans might be able to discern his zodiac sign. The rest of the Hawkeye characters might be a bit more of a challenge.
Hawkeye features as many antagonists for the titular character as it does allies, and a lot of them would agree with Clint that they don't need to know anything about their zodiac sign at all. Others might enjoy teasing some of the people they know with their zodiac knowledge, like Yelena Belova, for one.
Aries: Jack
Inspired by the comic book character Swordsman, Jack tries to be a charmer. He's warm and passionate about his interests, but Kate (and the audience) doesn't trust him right away.
Jack's passion and tendency to jump into situations without thinking make him a lock for Aries. Aries are the first fire sign of the zodiac, and they're often characterized as impulsive. While Jack doesn't seem extremely impulsive, he does grab a sword and decide to fight off the Tracksuit Mafia without really knowing what's going on, and he does pull a sword on Clint and Kate when he finds them in the apartment. He's quick to react.
Taurus: Maya
Taurus is often considered the most stubborn sign of the zodiac. This is the sign that holds grudges, resists change, and enjoys a predictable routine. Taurus also tends to be one of the more protective signs of the zodiac. All of these traits can be found in Maya.
Maya is driven to rise up in Wilson Fisk's ranks because of her father's death. She wants revenge on the person responsible, even if that person turns out to be her uncle. She doesn't take kindly to Kate interfering in her efforts to find the Ronin, or being betrayed by Kazi.
Gemini: Grills
When Grills is first introduced at the LARPing event in the park, he's friendly, excited, and completely ready to help Hawkeye out — as long as Clint is willing to help him out in return. Over time, it's clear that Grills has got a great group of friends and he thinks quickly on his feet.
All of that adds up to Grills being a Gemini. Geminis are social butterflies. They're able to fit in anywhere because of how well they adapt to their situation, and Grills certainly shows that ability as he becomes Hawkeye's ally. He rolls with what it means to work with a vigilante and even gets more of his friends to help.
Cancer: Laura
The final episode of Hawkeye reveals that Laura has a S.H.I.E.L.D. connection beyond her husband. Despite a secret agent past, she has never come across as duplicitous, but incredibly grounded, welcoming, and someone who sees the good in people. After all, she's close enough with former Red Room operative Natasha Romanoff that her children call her Auntie Nat.
Laura is definitely a Cancer. While Cancers have a reputation for being overly emotional, Laura doesn't show that side. Instead, she demonstrates a Cancer's caring nature and ability to form lasting bonds and make fast friends.
Leo: Kazi
When the audience is first introduced to Kazi, he mainly stays in the background. He seems like he's Maya's support system amongst the Tracksuit Mafia, but that turns out not to be entirely true. He's jealous of Maya's spot at the top, and his loyalty actually lies with Wilson Fisk.
Kazi is a Leo, but one who hasn't been in the spotlight in a long time. Leos love attention, which is why they tend to be performers and leaders in a lot of fictional depictions. Kazi demonstrates that when a Leo doesn't feel the love and attention they crave, they can allow jealousy to rule them.
Virgo: Eleanor
Comic book fans watching the show suspected Eleanor Bishop might not have been upfront with her daughter from the beginning, but that doesn't mean Eleanor doesn't still love her daughter. In fact, she's still a nurturing Virgo, just not in the way the audience would expect.
Eleanor is very focused on keeping Kate safe, and that manifests in her hidden deals with Kingpin, protecting Kate from a world she believes is too dangerous. She even plans for eventually leaving that world with records to use as insurance against Wilson Fisk. Eleanor is also a meticulous planner, evident by her decor, her holiday party, and the security business she runs. Eleanor is very much a Virgo.
Libra: Wendy
Wendy, aka Bombshell, is a friend of Grills and an organizer for LARP meet-ups. She has a lot of the same charm as Grills, which makes perfect sense considering Libras and Geminis have a lot in common.
While Libras are natural leaders, they also work great in partnerships. The audience sees that in Wendy immediately becoming an ally for Clint, backing up Grills in the field, and working with Kate to get Clint his confiscated arrows back. Libras also have a strong sense of justice, so it makes sense that Wendy is a police officer who is still willing to break the law to help a vigilante like Hawkeye.
Scorpio: Natasha
Natasha isn't technically in Hawkeye, but her presence is all over the show as Clint grieves her loss and Yelena is motivated to kill him as a result of her sister's death. Canonically, Natasha's birthday makes her a Scorpio, and the sign certainly fits the Black Widow.
Scorpios are known for being mysterious and keeping their emotions to themselves until they can trust someone. They're also known for their love of puzzles and an aggressive approach to goals. Natasha, as both Clint and Yelena point out, is unstoppable when she wants something. When she decides to sacrifice herself, neither of them would be able to stop the Scorpio.
Sagittarius: Kate
Kate has a lot of the passion and impulsivity of an Aries, but she's also got the nearly unstoppable optimism of a Sagittarius. The sign is most often known as the philosopher because they love to talk, tell stories, and theorize. Kate talks so much when she first meets Clint, he even tunes her out.
Kate's optimism and desire to learn is good for her partnership with Clint though, and great traits to have if the MCU pushes toward a Young Avengers team with her. She balances out his pragmatic approach to his mission, helping loosen him up just a little bit while he's bogged down by his grief.
Capricorn: Clint
Clint Barton is canonically a Capricorn. Even if he wasn't, he would fit the sign perfectly. Capricorns are known for their loyalty, practicality, and intense work ethic. While many have grand ambitions as well, they are always working toward them.
For Clint, that ambition most often seems to do right by his family. He's incredibly loyal to S.H.I.E.L.D. and the Avengers when he works for them, but his entire motivation is to be a good dad. Clint doesn't just put in the work to be a hero, but to be there for his kids.
Aquarius: Fisk
Wilson Fisk doesn't appear much in Hawkeye as the Kingpin in the shadows, running the Tracksuit Mafia and helping keep Eleanor Bishop's business profitable. If the audience is already familiar with the Daredevil character, though, that's not a problem.
Fisk has a bit of Capricorn ambition in him, wanting to be in charge and wanting to leave his mark. He also wants to do it his way, though, which is where the Aquarius connection comes in. They're unique, the sign with the most creative solutions to problems, and the sign that walks their own path. Fisk is determined to do things his way and make sure everyone knows it.
Pisces: Yelena
Pisces is the dreamer of the zodiac, and fans might not see the Black Widow assassin as a dreamer, but Yelena certainly is. Despite being in New York to do a job, she's also ready to see the sights and make small talk with Kate Bishop.
Yelena, as a former Widow points out in a flashback, has a fantasy life in her mind of what she'll have in New York with Natasha once she frees the other Widows. Yelena doesn't get that, and when she doesn't, she uses her line of work to embrace her emotions, as a Pisces would as well. She gives in to her grief when she goes after Clint Barton.