- Roary is a young and enthusiastic junior single-seater racing car. He is the main character in the show and is Big Chris' "number one star". Roary is inexperienced and he often makes mistakes. However, with the help of his friends, he always learns from them. Roary wears a white baseball cap and with a number 1 emblazoned in a red star. Roary's catchphrase is "Light 'em up". He is voiced by Maria Darling.
- Maxi is an older yellow Formula 1 type racing car who was the star of Silver Hatch before Roary arrived. He is temperamental and expects the best of everything - including first use of the tyre warmers. He wears sunglasses and a blue cap and sports the number 5. Maxi is Italian and is the favourite of Mr Carburettor. Maxi's catchphrase is "Mamma Mia!" He speaks in an Italian accent, although this is de-emphasized in the US voiceover. When starting a race Maxi can make flames erupt from his exhaust. There is a healthy sibling rivalry between Maxi and Roary. He is voiced by Marc Silk.
- Cici is a bright pink and purple stunt car with a number 3 painted on her front. She is an electric car and carries solar panels on her roof. She has a flirtatious attitude and is always challenging Roary to "Catch me!" Cici is French and has a high, squeaky French accent. Her catchphrase is "Race you!". She is one of Roary's best friends and the first car to talk to and race Roary on his first day. Cici seems to have crush on Maxi, though Cici is often very impressed by Roary as well. She is voiced by Maria Darling.
- Tin Top is a big and powerful stock car. He often takes his corners too fast and wide and regularly ends up in either the sand trap, the tyre wall or the mud, generally in a tangled heap of disconnected parts. Tin Top's catchphrase is appropriate given his frequent visits to the workshop: "Tape me up, hammer me in and send me out!" He sports the number 88 speaks in a mock-American accent, and is voiced by Peter Kay. Like Maxi, Tin Top can make flames come out of his tailpipes. In the US version, Tin Top speaks in a stereotypical "urban" accent, and does not seem to have a catchphrase. He is voiced by Tim Whitnall.
- Dragga is a very hi-tech Drift racing car. In line with his name he can be observed to exhibit extreme oversteer handling characteristics, with his tail end swinging out wide on every corner. He has an on-board computer with a head up display in his windscreen. Dragga has a fabulous dragon on his sides and also sports blue neon undertray lighting and he wears the number 6 on the top of his front windshield and back windshield. He speakes in a mock Japanese accent. Dragga's catchphrase in the UK version is "Go-go nitro boost!"; he does not have a catchphrase in the US version. He is voiced by Marc Silk.
- Rusty is an old, rusty, immobile caravan who lives at Silver Hatch. He is often found to be sleeping, but rarely minds being woken up by the other characters and he enjoys reminiscing about his time as a mobile caravan. He can give useful advice, but often entirely by accident. Big Chris lives in Rusty. He is voiced by Tim Whitnall.
- Plugger is a 4x4 off-road vehicle, or "mud-plugger". Plugger is the most laid-back character at Silver Hatch and he never gets rushed or panic-stricken. In the UK version, he speaks with a soft Caribbean accent; in the US version, he speaks in a mild Southern drawl. He often uses his telescopic winch to rescue Roary and Maxi from mud, gravel, or sand. Plugger can often be heard uttering his catchphrase "No need to race, Plugger's on the case!"
- FB is Farmer Green's pickup truck. He is usually seen with Farmer Green, or playing with Cici and Roary. His main catchphrase is "Roary's my best friend". He is voiced by Marc Silk.
- Zippee is Marsha's motor scooter. Zippee is of indeterminate gender as the only vocalizations made by Zippee are a beeping sound, similar to a small car horn. She is voiced by Maria Darling.
- Hellie is a bright red and purple helicopter, who transports Mr. Carburettor around the track. He has a large headset which he uses to communicate with the ground-crew, usually broadcasting a booming "Hellie is Go!" In the UK. He is voiced by Tim Whitnall.
- James is a silver classic sports car approximating an Aston Martin DB5, who takes Mamma Mia wherever she needs to go. He has several gizmos and gadgets including an ejector seat, an umbrella, water cannons and a towel. His catchphrase is, "The name's James", and he speaks with a posh British accent.
- Nick is the Silver Hatch police car approximating a Lamborghini Gallardo or Murciélago, who works with P.C. Pete to keep the cars safe. He enjoys playing with the other cars and he wishes he could race with them too. His catchphrase is "Wicked!" In the UK version, he is voiced by Neil Morrissey and Rob Rackstraw. In the US version, he is voiced by Greg Proops.
- Breeze is a beach buggy who lives at the beach at Silver Hatch. She is good at stunts, like Cici, and loves it when the other cars come to visit. Her catchphrase is "Life's a breeze", and speaks with a very fake Australian accent. She is voiced by Emma Tate.
- Loada is a transport truck who takes the cars to special occasions. He has lots of different stories from the road and he enjoys telling them to his friends. His catchphrase is "Lock n' Loada", and he has a slight Italian accent. In the UK version, he is voiced by Ron Smith. In the US version, he is voiced by Colin Fox.
- Conrod is an Australian race car who is named after the stretch of racetrack at the Mount Panorama Circuit in Bathurst, New South Wales. He has a big noisy V8 and arrives without warning at Silver Hatch. In the UK version, he is voiced by Australian V8 Supercar champion Craig Lowndes. In the US version, he is voiced by Robert Tinkler.
- Big Chris (Voiced by comedian Peter Kay) is Silver Hatch race track's mechanic. He occasionally commentates, and starts races. He lives in Rusty the caravan, and looks after the race track and cars. Big Chris has a typically northern catchphrase, "You bend it, you mend it." (The US version, much less mellifluous, is "You bend it, you fix it.") Big Chris is portrayed as being very messy and absent-minded, often "losing" objects directly in his line of sight, and eternally surprised by his own walkie-talkie. While working on the cars, he often practices his karaoke with an out-of-tune version of a song called "Motor Man". He is voiced by Kerry Shale, who also sings the US version of the theme.
- Marsha is a race marshal and the unofficial administrator of the Silver Hatch race track. She loves things to be tidy and organised, which often puts her into conflict with Big Chris. She is very fit and enjoys a good run. She speaks with a thick British accent and her UK-version catchphrase is "Gears to go, brakes to slow!", while in the US version she has no catchphrase. She is voiced by Maria Darling.
- Mr. Carburettor is the flamboyant owner of Silver Hatch race track. In the original UK version, he speaks with a pronounced Italian accent, while his US counterpart has a New York accent. His favourite car is Maxi, who he considers to be the greatest car in all the world. He has a gold tooth, which sparkles in the sun when he smiles. He has a quick temper, often turning red, making steam come out of his ears and yelling that the object of his anger is "driving me up the ceiling!" He is a perfectionist who sometimes berates Big Chris for tardiness, although Marsha often covers for Big Chris in front of Mr. Carburettor. Mr. Carburettor often likes to watch his cars race around the track, usually cheering for Maxi, although he does congratulate the winner, whoever it may be. He shares the same catchphrase as Maxi, "Mamma Mia", and he can often be heard singing opera. For some reason Mr. Carburettor can't say Tin Top's name right. His first name has been revealed to be Antonio. He is voiced by Tim Whitnall.
- Farmer Green owns the farm located just to the side of the Silver Hatch race track. He often waves as the cars zoom past. He owns Dinkie the Donkey, and likes to invent bio-fuels, which sometimes work, but often don't. His UK catchphrase is "Green by name, green by nature!", though like many of the other characters, his US counterpart has no catchphrase. He is voiced by Marc Silk.
- Mama Mia is Mr. Carburettor's mother and the owner of James. When she first visited Silver Hatch, it was thanks to Flash that she enjoyed the race (which resulted in every car except Roary crashing). Now she is a regular visitor to the racetrack. Her catchphrase is "Home James", and she speaks with an Italian accent. Voiced by Robert Tinkler.
- P.C. Pete is the Silver Hatch policeman and Marsha's younger brother. When he sees one of the race cars speeding away from the track, he calls to his police car, Nick to follow them. His catchphrase is "Follow that car", and he is voiced by Todd Duffey.
- Flash is an anthropomorphic rabbit, who lives under a tree on the edge of the track at "Hare-Pin Bend" (a play on 'hairpin turn'). He regularly tries to cause mischief, from small things like hiding equipment to intentionally trying to cause accidents by moving traffic cones around to divert the racing cars the wrong way. Flash really wants to be a racing driver and often challenges the Silver Hatch cars to race against him as he rides his high-powered skateboard. When Flash is caught getting up to no good you will often hear his catchphrase: "Flash must dash!" In the US, he has several catchphrases: "Furz...must fly!" and "Chew my carrots!" being two oft-repeated ones. Voiced by Marc Silk.
- Molecom is a bespectacled mole who is often found clearing up the mess left behind after Flash has tried to cause havoc. Being a mole, he lives underground, and often digs out, causing molehills to appear when he comes up. By some kind of sixth sense, Molecom never seems to dig out through the track, although is often seen digging out through the concrete pit stop area. His catchphrase is "I'm a mole with a role". Voiced by Maria Darling.
- Dinkie is an old, grey donkey who is often seen at the side of the race track (and occasionally on it), with his ears flapping after the cars race past him. Dinkie's vocal effects are performed by Tim Whitnall.
- Roary will meet Alvin Seville, Winnie the Pooh, Baby Kermit, Twilight Sparkle and the characters in Chipmunks Tunes Babies & All-Stars' Adventures of Roary the Racing Car (TV Series).