Jonas "Snake Doctor" Blaine
- "You been training for this moment your entire life. The universe has been conspiring, if you think about it, to put you right here... right now. Off you go, we're all waitin' on ya."
- A Father to His Men: Frequently seen dispensing wisdom and advice to his men, and watching out for them.
- Benevolent Boss
- Bald Black Leader Guy: He could be a poster boy for this trope.
- Papa Wolf: The calm cool type, mostly. When his daughter is kidnapped by terrorists, he walks into a Syrian mosque, reveals himself to be wearing an explosives vests, and tells the congregation that he's willing to kill them all and himself if nobody helps them. What's truly terrifying is how calmly and matter of factly he says it:"Cool Breeze, Betty Blue. I will count to three. When I get to two, leave the room. The next thing you hear will be an explosion. When that happens, find my daughter. One. Two. God forgive me."
- Ranger: Graduated Ranger School and was awarded the Ranger Tab. The show implies that he served in the 75th Ranger Regiment before getting his green beret.
- Scary Black Man (subverted in that he's not that scary. Usually. Until his daughter is kidnapped. See Papa Wolf.)
- Sergeant Rock: The leader of Alpha Team.
Bob "Cool Breeze" Brown
- "How do you think we got in here, you think we were sitting at the 7-Eleven next door? We had to muster up, fly in, parachute in four miles away, hike in here and not get our asses shot off so we can get your asses out! We are your last line of defense sir, we are the cavalry."
- Badass Bookworm: He can also fly planes and helicopters. A rarity for a enlisted Soldier in real life.
- Blood Knight: Called out by Betty Blue... later he himself understands this and accepts it.
- The Cavalry: Bob was serving in a Cavalry Diviision before being selected for the Unit.
- The Charmer
- Friendly Sniper: Bob is a friendly, nice guy, who also happens to be the best sniper of the team.
- Guile Hero: However, he is not averse to using weapons when needed
- Ranger: Like all the others, a Ranger graduate.
- Sesquipedalian Loquaciousness: Being the only member who went to college, oh indeed. He was supposed to go to law school, originally.
- Smart Guy: Of the five man band.
Mack "Dirt Diver" Gerhardt
- "Just when everything was going so well."
- Badass Beard: He sports a very badass beard.
- Deadpan Snarker: One of his coping mechanisms.
- Domestic Abuser: Heavily implied, although Tiffy gives as good as she gets.
- The Lancer: To Snake Doc's Hero.
- Manly Tears: In Whiplash, when he was asked the pledge.)
- Papa Wolf: Yes, the gun in your face type.
- Ranger: Like all the others, a Ranger graduate.
- Stepford Smiler: His wife is sleeping with his morally ambiguous superior officer, who could send him to his death if he ever felt like it and who gets away with the affair once it becomes public knowledge. Furthermore, it's implied that he has a borderline abusive relationship with his wife and that, while their circle of friends are aware of it, the two are forced to put on a front of being a happy couple for everyone else. Especially after the affair is exposed.
- Weapon of Choice: The Throwaway gun.
- Villainy Discretion Shot: Several episodes in the show's run implied, if not danced around, the fact that Mac was verbally abusive towards his wife Tiffy and that on multiple occasions been physically aggressive towards her when the two fought. None of it is shown on screen however, due to the couple being a pair of Stepford Smilers.
- Cuckold / Your Cheating Heart : Tiffy has cheated on him with Col Ryan, but in one episode, he has a drunken one night stand with a character played by Summer Glau
Charles "Betty Blue" Grey
- "Yeah... I have a plan. You wanna be some help, or I'm gonna use you for parts? We're gonna take them down."
- The Big Guy: Of the crew.
- Bomb Disposal: Seems to be the explosives expert of the team.
- The Bro Code: Grey worries he is in violation of this when he starts to date Hector's former girlfriend after Hector's death.
- Cunning Linguist: He speaks Arabic, Korean, Portuguese, and Spanish.
- Those Two Guys: Him and Hector, especially in Season 1.
- Warrior Poet
Hector "Hammerhead" Williams
- Ambiguously Brown: Hector has passed for more nationalities than anyone on the team.
- Black Dude Dies First: First member of The Unit to buy the farm.
- Combat Medic
- Killed Off for Real
- Those Two Guys: Him and Charles Grey, especially in Season 1.
Sam "Whiplash" McBride
- Fake Defector
- Le Parkour
- Throw Down the Bomblet (his grenade use almost cost him entrance to The Unit)
Bridget "Red Cap" Sullivan
- Beware the Nice Ones: "Best Laid Plans" has Red Cap rather chillingly ending a weapons dealer's life by lethal injection. This is definitely not the first time she's done this sort of thing.
- Ms. Fanservice
- The Squadette: Only partly - she is not a full member of The Unit.
Tom "Dog Patch Zero Six/Blue Iguana" Ryan
- "Where your bodybag? Exactly. But each member of the Unit carries their own bodybag. So until you carry one you don't deserve to talk to my men about their code. They sign on to not exist, for them there is no legacy. These men die for each other, not for you or your boss. These men are warriors. You think need to remind them about their code of silence? They answer to a higher code, friend."
- Colonel Badass
- Da Chief
- Death Seeker: Has shades of this during the mission to rescue Betsy Blaine, when he keeps provoking the terrorists to kill him, and later volunteers to Hold the Line for the escape.
- Knight Templar
- The Plan: Runs one when Jonas' daughter is kidnapped and they're investigating in Iraq. He pretends to have a heart attack so that he's injected with a medical radioactive isotope, then lets himself be kidnapped by the terrorists; the isotope allows him to be tracked for a rescue to come.
- My God, What Have I Done?: After witnessing her husband murder a traitorous couple in cold blood (albeit under orders), rendering their baby an orphan, Kim has a brief moment of this when she realizes that she facilitated the act in part by helping her heroin-addicted husband "steady his hand" so he could take the shot.
- The Watson