|Melinda Qiaolian May|
|Portrayed by||Ming-Na Wen|
Agent May is an extremely intelligent woman who presents a stoic, rather uncommunicative demeanor at all times. According to Agent Coulson, earlier in her career May was a much friendlier person, prone to playing pranks on her fellow agents and generally happier, though still rather quiet. A tragic experience while on a mission in Bahrain to contact an unregistered gifted individual left May emotionally scarred and caused her to become the rigid, somewhat withdrawn person she is today. She is frequently the pragmatist to Coulson's more humanitarian approach, for example, in "Repairs" when she tranquilizes Hannah Hutchins to ensure the situation does not escalate. May is fiercely loyal to her S.H.I.E.L.D. team ,and more specifically Agent Coulson, and will do whatever it takes to keep them safe. Sometimes her methods appear harsh but this is due to her dedication to protecting those in her charge.
May is an Asian female with brown hair and brown eyes, her height is about 5'6".
May is a top-notch pilot, and remarkably skilled at martial arts. She was a resourceful and good field agent, earning the nickname "The Cavalry", apparently at least in part due to unspecified events in Bahrain ("0-8-4"). She was so talented at her job that she became a legend within the agency. Despite leaving the field a while ago, she still retains her licence and training to fly an airplane.
May used to be a field agent for S.H.I.E.L.D., and was highly skilled at her job. During her time as a field agent, she became somewhat of a legend at the agency. 
On a mission in Bahrain to make first contact with an unregistered gifted person, several of Agent May's colleagues and a young civilian girl were taken hostage by the man's followers. Agent May single-handedly stormed the building in which the hostages were being held and killed an unknown number of assailants, all while unarmed herself. She managed to free all of the hostages unharmed. However, the experiences May had on that mission, which she refused to fully disclose to Phil Coulson, left her emotionally scarred and caused a radical change in her personality. After this mission May attained almost legendary status within S.H.I.E.L.D. for her exploits, which earned her the nickname "The Cavalry." (Repairs)
In "Turn, Turn, Turn" May states that she put together the team, by essentially guiding Coulson to chose the people she would need, including the tech-bio combo of Fitz and Simmons and Ward as a specialist, if it became necessary to put Coulson down.
Throughout "Providence" and the early part of "The Only Light in the Darkness" May attempts to justify her actions to Coulson and rebuild at least a modicum of trust. "Phil", however, as she calls him during this endeavor, is having none of it, and by the end of the latter episode May has struck out on her own, leaving the base and meeting up with her mother, apparently with the intention of seeking out Maria Hill. This may, however, still be part of a last-ditch desperate effort to reconnect with Coulson. In that same episode it was revealed that she was once married.
Phillip Coulson: Friend, colleague and team leader (a deeper bond has been hinted at). She is, however, monitoring Coulson's investigation of his own death for Nick Fury. However much his faith may have been shaken, by the conclusion of "Beginning of the End" Coulson appears to rely upon her once more.
Grant Ward: Former colleague and "friends" with benefits (the latter is not to be made public, as evidenced by the flat, angry glare she gives him at the start of "The Bridge", when, during a sparring session on The Bus, he alludes to it. He later speaks of the issue directly, saying he can 'separate Church from State'). She informed Coulson in "Seeds" of this, saying, "Agent Ward and I have been having sex . . .", and later confirming that he had heard her statement. It is revealed that Ward was having sex with her in order to gain her trust. In the end she has a huge fight with him, breaking his throat and shooting nails into foot.
Jemma Simmons: Colleague
Skye: Colleague, trusted but not completely. Skye dredges up painful issues, and provokes unwanted questions, causing May to occasionally, perhaps unintentionally, use her to vent her own frustrations. May, however, seemed more than willing to beat Ian Quinn to death with her bare fists for shooting Skye.
Antoine Triplett: As yet unknown, although they would seems set to be colleagues.
- Melinda - "Gentle" 
- May - Likely to be 梅 in Mandarin Chinese, which means "plum" or "prune".
- Qiao - Likely to be 巧 in Mandarin Chinese, which means "ingenious".
- Lian - Likely to be 蓮 in Mandarin Chinese, which means "lotus flower"
- Therefore, her full name in Chinese is 梅巧蓮.
- Her current ID badge serial number is A 078624; the card was issued on 4 September 2013, and will expire on 4 September 2019.
- Melinda is helping Coulson figure out what happened to Skye's parents.
- Also known as The Cavalry.
- Has been married once.
Jemma Simmons, Leo Fitz: She's the cavalry?
Melinda May: I told you never to call me that.
"Girl in the Flower Dress"
Coulson: Go ahead, say it.
May: I don't do petty.
Coulson: But you called it. I trusted my gut even though you said she was a risk.
May: When someone breaks into my house, I usually don't invite them to stay. But that's me.
Coulson: That's me too. Then that alien staff went through my heart.
May: Sure it didn't go through the brain?
Coulson: You really don't do comforting either, do you?
Coulson: I can't think of a single time when anything alien in human hands ended well.
Skye: Wouldn't mind getting my human hands on Thor. He's so dreamy...
Coulson: Sure, he's handsome, but-
May: No. He's dreamy. [Walks on. The other two stare after her, somewhat surprised.]
Melinda May: You taking a punch for me. I don't need your protection.
Grant Ward: You think I don't know that? I took that punch because you're faster than me. You can do more good on your feet. It was tactical not personal.
Ward: Really? You think Coulson will take that excuse if he finds out about us?
May: He took it okay when I told him.
Ward: Wait? You told him?
Melinda May: If Coulson thinks there's a chance in a million to save Skye, to save any of us, he'd take it. People like us, we need people like him.
"End Of The Beginning"
Melinda May: You don't believe in the Clairvoyant, but you believe in astrology?
"Turn, Turn, Turn"
Melinda May: I evaluated what was needed, and I gave the assessment to Fury, and he gave you parameters for your unit.
Phil Coulson: What was needed, May?
Melinda May: Someone who could repair your body, a technician who could reprogram your brain, and a specialist to help me put you down if it had to be done. But I didn't do it for Fury. I did it for you, to protect you! I - You mean a lot to me. A lot. To hear you were dead... you may not believe me, but that's the truth. And I have nothing to do with the clairvoyant or this Hydra threat we're up against. Hopefully this helps prove that.
Phil Coulson: I want to believe you... But you've used that against me this whole time.
Melinda May: I'm furious, but I sure as hell am not going to waste it on a tantrum. I'm gonna mine it, save it, and when we find Ward, I'm going to use every bit of it to take him down.
"Beginning of the End"
Kaminsky: If it isn't the Cavalry.
Melinda May: [Kicks him in the stomach] Don't ever call me that.