- Nice Guy: He's a very pleasant, kind-hearted person and rarely (if ever) loses his temper.
- Butt-Monkey: If it's not Trevor, Mike, or Charlie getting into scrapes, it's Elvis.
- Genius Ditz: He may not be very bright, but he's extremely competent at his job.
- Lethal Chef: A Running Gag is that his food is absolutely atrocious. Although, considering neither Sam nor Steele have ever tried their hands at cooking, one has to wonder how much worse THEIR food would be.
- Lethally Stupid: In "Fox on the Run", he feeds Radar chocolate (which can kill dogs), mistaking it for doggy treats. Radar was sick, but at least he didn't die.
- Nice Guy: Though not very bright, you'd be hard-pressed to find someone nicer than Elvis.
- No Celebrities Were Harmed: Need we say more?
Station Officer Steele
- Catchphrase: "Now who needs the Fire Service?" (in the first four seasons) and "Action stations, men!" (in the fifth season only).
- Cool Old Guy: Much more pronounced in the CGI seasons, in which he tries to hide hobbies such as paper airplanes and kite-flying from the others (though he does bond with Norman over the former, and Elvis assures him the kite is nothing to be ashamed of).
- Jerk with a Heart of Gold: He can be rather strict and bossy, but he cares very much for the well-being of his firefighters and the people of Pontypandy.
- Butt-Monkey: Everything that can go wrong for Trevor inevitably does.
- Nice Guy: The man is a massive sweetheart, popular with both the kids (whom he affectionately calls "my sugarlumps" in the classic seasons) and the ladies.
- Action Girl: Comes with being a firefighter.
- Ascended Extra: Penny was introduced in the third season as a recurring character from Newtown. By the fifth season, she had transferred to Pontypandy full-time.
- Nice Girl: Nice to everyone, and never angry unless given a very good reason.
- One of the Kids: Tends to get into misadventures with the children.
- The Smurfette Principle: Until Ellie Phillips was introduced, Penny was the only female firefighter in the series.
- Put on a Bus: She disappeared after the fifth season, though her cafe was still visible across form Dilys' store.
- The Bus Came Back: She eventually returned in the tenth season with a new design and a reason for her absence: moving to Newtown between the fifth and sixth seasons.
Sarah & James
- Catchphrase: James would often say "Mega-Brill!" (short for "mega brilliant") in the classic seasons.
- Hair of Gold, Heart of Gold
- Idiot Ball: They hold it several times in the CGI seasons, whether individually or together, especially if it involves their Sibling Rivalry going too far.
- Only Sane Man: They tend to be the most-rational kids in Pontypandy.
- Sibling Rivalry: They tend to bicker in the CGI seasons, in contrast with the first five seasons where it was limited to the occasional good-natured jab.
- Adaptational Jerkass: Norman's a lot crueler in the CGI seasons compared to the first 5 seasons. For example, Norman in the first 5 seasons would never have tied James to a chair and left him in a room set on fire, nor would he have trapped James in the swimming pool changing rooms by gluing the door shut.
- Disappeared Dad: Norman's father has never been seen or even referenced. Maybe this is part of the cause of his behaviour?
- Four Eyes, Zero Soul: Norman wears glasses and is a prankster.
- Jerk with a Heart of Gold: Despite his love of mischief, he often becomes a hero by summoning help for others in need.
- Too Dumb to Live: Sometimes the reason he ends up in danger.
- Took a Level in Dumbass: In addition to being crueler in the CGI seasons, Norman is also much more stupid. Whereas his pranks in the first five seasons were planned out in advance, in the CGI seasons, he's a Leeroy Jenkins who goes for it without thinking about the consequences.
- Hidden Depths: Despite being well-behaved most of the time, he's actually just as much a prankster as his cousin Norman.
- Nice Guy: Normally soft-spoken and polite.
- Pallete Swap: His character model is Norman's with a couple of differences, such as brunette hair instead of ginger, different-colored clothes, and no glasses. They both have the same voice actor, as well, though Stephen Kynman gives Derek a West Country accent while Norman's is distinctly Welsh.
"Well, you heard it here first, Space Spotters! Fireman Sam says that aliens in Pontypandy are not from mars! They're from a much more distant planet!"
A new character for the 2017 special "Alien Alert". He is an alien hunter and a television presenter for the TV show "Alien Quest".
Don Sledgehammer (AKA Don Bloomburg)
Voiced by: Kerry Shale (UK and US)
A new character for the 2018 Fireman Sam special. He is the director of the movie that Fireman Sam and Flex Dexter are going to star in.
Another new character for the 2018 Fireman Sam special. He is the co-star and nemesis to Fireman Sam for the movie they're starring in. He is an actor that doesn't like to be out of the limelight, and as soon as Fireman Sam gets the lead role, he gets very jealous and wants revenge against the hero next door.
A new character who is the main antagonist of the 2020 Fireman Sam special "Norman Price and the Mystery in the Sky". She is the first female antagonist in the "Fireman Sam" franchise.
Voiced by: Kerry Shale (UK and US)
The secondary antagonist of the 2020 Fireman Sam special. He's more of a bumbling Anti-Villain
who is known to be clumsy and dotty, much to Professor Polonium's chargin.