The show was known for many memorable lines of dialogue which included:-
- "Get yer trousers on, you're nicked." This line became synonymous with the show, although it was only ever used in the pilot episode, "Regan". Despite the line's Sweeney associations it was actually first used in Euston films series "Special Branch", in the episode 'Date of Birth'.
- "SHUT IT!" This line is most associated with The Sweeney, although Regan only ever uses it in a couple of episodes and the first feature film.
- "We're The Sweeney, son, and we haven't had any dinner. You've kept us waiting, so unless you want a kicking you tell us where those photographs are." (Ringer)
- "Cor, that Sheila has got some lunch on her!" (Queen's Pawn - Carter is admiring Sheila's cleavage as she dances)
- "The world does not revolve around your body. This bloke Galileo proved it, it goes around the sun." (Night Out)
- "I hate this bastard place, it's a bloody holiday camp for thieves and weirdoes, all the rubbish. You nail a villain and some ponced up pin stripe Hampstead barrister screws it all up like an old fag packet and pops off for a game of squash and a glass of Madeira. He's taking home 30 grand a year and we can just about afford 10 days in Eastbourne and a second hand car. Nah, it's all bloody wrong, my son." (Abduction)
- "The hairs on my wooden leg tell me that something is up." (Abduction)
- "You couldn't find an Irishman in a Harp Club." (Abduction)
- "He's a weirdo and he's hard enough to rollerskate on." (Stay Lucky,Eh?)
- "If you weren't who you are, I'd kick your arse up to your shoulderblades." (May)
- "Now the question is: do I write my statement and then get drunk, or get drunk then write it?" (Taste of Fear)
- "Nah, course I wasn't scared. Mind you, some bugger peed in my pants." (Taste of Fear)
- "You shall go to the ball" (Carter gives Regan a pair of muddy shoes dredged up from a river as evidence: a mocking reference to Cinderella)
- "I am utterly and abjectly pissed-off with this little lot. I've given the best years of my life to the job. I've got eighteen bloody commendations, if you include the one I didn't get yesterday. And how does this 'wonderful' police force show its gratitude for all my years of unstinting effort? It bangs me up in a crummy little cell like some cheap little villain - all because a toerag called Hutchinson's got a few bottles twitching on the Fifth Floor. Now, because that poor little bastard had the guts to get off his arse, I'm going to have to be reinstated. And what do you bunch of bleeding double-dyed hypocrites want now? You want me to crawl back to work and be terribly grateful that I didn't get nicked for something I didn't do. Well you can stuff it!" (Jack or Knave - Regan is accused of being corrupt)
- "I'm gonna come down on you so hard your going to have to reach up to tie your shoe laces."
- Regan: "Ere George. You ever fancied a gaff in the country?" Carter:"Wot on a copper's bunce? Leave it out guv!"
- "We're The Sweeney! We kill you - nothing! You kill us - thirty years!" - Det. Insp. Jack Regan (pilot, Regan)
- "He's got a bloody rifle!" (Regan, Trojan Bus)