Paxton, nicknamed "Pax", is a young, dark green diesel engine. He often brings slate down from the Blue Mountain Quarry to other parts of the Island. He is friends with Diesel, although Diesel prefers to play tricks on Paxton rather than be friendly with him.
Paxton was one of the diesels who took over the Sodor Steamworks. Paxton works at the Blue Mountain Quarry and was once involved in an accident there when Blondin Bridge collapsed. He was then sent to the Sodor Dieselworks for repairs.
Upon his return to work at the quarry, Paxton overheard Luke telling Thomas about how the little green engine knocked a yellow engine into the sea. Paxton told Diesel about what he had heard. Diesel decided that Luke should be punished and set out with Paxton to expose Luke. However, Paxton felt bad and helped Thomas and Luke out by bringing Victor to talk to Luke and the Fat Controller.
Paxton almost got into a collision with Winston when he was a runaway, but luckily he stopped just in time. Afterwards, he warned Gordon to be checked over after an accident with stone. When Gordon ignored his warnings and broke down, Paxton brought him to the Steamworks to be repaired.
After Sir Topham Hatt told Paxton among other engines to be careful near the bumpy track, Paxton then messed around on the damaged track with Thomas, causing Thomas to collide with Toby. After Toby says Thomas "Lost his puff" Paxton searches for the "Puff" and makes himself look silly in front of Stephen and Victor. He then learns that "Puff" means steam. He was later used by Diesel 10 to steal Christmas decoration from Tidmouth sheds, but soon lost patience and left to collect the truck Sir Topham Hatt told him to collect.
Diesel once got the other diesels to hide from him, but Paxton eventually found him, stranded on the branch line, with no fuel, and shunted him to the next station for him to stock up.
At Christmas time, he was given the job of transporting a Christmas tree to Ulfstead Castle. But the tree caused him to derail, and when Diesel passed by, he refused to help Paxton. That night, Paxton pretended to be the Ghost of Christmas Present to try and remind Diesel of the true meaning of Christmas, but Diesel was too scared to listen and ran away.
Paxton is a young, gentle diesel who often works in or around the Blue Mountain Quarry and the Vicarstown Dieselworks. He is good-hearted and well meaning, but gullible, naïve, and easily misled. He also has a short attention span. He tends to be more of a follower than a leader and can sometimes find thinking for himself and making big decisions difficult. This may result in him being pressured into a situation he might not necessarily be comfortable with. However, if a friend is in trouble, Paxton will have the conscience and the self-assertion to do what he himself feels is right. As a result, the other steam engines find that he is likable and Paxton particularly looks up to Thomas at times. He also works alongside the narrow gauge engines frequently. However, Paxton can easily misjudge situations, misplace his trust in someone who might not have everyone's best interests at heart, and is a rather impressionable diesel, but his good nature will ultimately show him for who really wants to be.
Paxton is painted dark green with yellow lining. His traction rods and front bufferbeam are painted a rusty orange colour. His paint is chipped in places, and shows signs of weathering.
- Keith Wickham (UK/US; Day of the Diesels only)
- Steven Kynman (UK/US; Blue Mountain Mystery onwards)
- Martin Brücker (Germany; Blue Mountain Mystery only)
- Tobias Diakow (Germany; King of the Railway onwards)
- Kunihiro Kawamoto (Japan)
- Dariusz Błażejewski (Poland)
- Scott Maurstad (Norway; Blue Mountain Mystery onwards, excluding the seventeenth season)
- Christian Greger Strøm (Norway: seventeenth season only)
- Reinder van der Naalt (The Netherlands, until nineteenth season)
- Kaihiamal Martínez (Latin America)
- Troells Toya (Denmark)
- César Emilio (Brazil)
- Carlos Moreno (Spain)
- Anton Savenkov (Russia; nineteenth season onwards)
- Despite Paxton's nickname being "Pax", he has been consistently referred to by his full name rather than his nickname. He shares this dilemma with Norman and Sidney.
- According to the Licensing Source 2015 book, Ian McCue, current producer of Thomas and Friends, stated that Paxton is his favourite character.
- Paxton was never named in Day of the Diesels with the exception of the song.
- Paxton is the second character to break the fourth wall: the first was Stafford, followed by Rocky and Percy.
- Paxton: "Um...er...excuse me! Um...I-I-I wonder if, er, someone could help me? M-maybe? Please?" (thud) "...Ow."
- Paxton after being buried in the rubble from Blondin Bridge, Blue Mountain Mystery
- Paxton: "Hi, Stephen. Thomas lost his puff and I'm trying to find it and...well, I thought that might be...the lost puff...up there..."
- Stephen: "Up there? Well, that's just a cloud..."
- Paxton: "Yes, of course. I knew that. A cloud. Okay...got to go. Great to see you. Bye, Stephen."
- Paxton talking to Stephen about Thomas' "lost puff", The Lost Puff, seventeenth season