Oliver is a wise old excavator, who works for the Sodor Construction Company. He carries out demolition and digging work. He is capable of switching between different tools, including his usual bucket, a chisel for digging, a scissor claw, and a wrecking ball for demolition.
Thomas & Friends
In his first appearance, Oliver was helping to clear room for new railway lines at the quarry. Later, the foreman assigned Oliver to move some rocks, but Jack wanted to do it and instead toppled over a hill. Jack learned his lesson and after that he allowed Oliver to continue with his jobs. Once, Oliver uncovered a complete dinosaur skeleton while digging a swimming pool. The following day, Oliver was on the front page of the Sodor Times with the headline, "Digger Digs Dino!".
When Max and Monty carelessly crashed into the lightning tree, Alfie, Kelly and Oliver used their arms to prevent the tree from falling over until it was propped and saved. However, he proved to be unsuccessful after trying to demolish a building with a wrecking ball. In The Great Discovery, Oliver, along with the rest of the Pack, helped with the restoration of Great Waterton.
In Sodor's Legend of the Lost Treasure, Oliver helped to construct the Harwick Branch Line. One day when he was heading to the site, he blocked Bertie who was very annoyed since he lost a race with Thomas. When Marion first met the excavator, she believed that Oliver the engine had made a wish to Rex, Bert and Mike, who Marion believed to be magical, to turn himself into an excavator. Oliver tried to explain, but Marion gave the excavator no chance to do so. It was not until the opening ceremony of the new branch line that Marion found out that there were two Olivers on Sodor.
In the twentieth season, when he, Jack, Alfie, Max and Monty were working on Thomas' Branch Line the dump truck twins caused a rock to hit Oliver's hydraulics in his arm causing him to have to repaired and when he was repaired he helped clear the branch line after Max and Monty dump their loads on the line.
Oliver is wise and kind and keeps an eye on the other members of the Pack. He is good-mannered and hard-working and never complains about his work or gets impatient. He has the power and precision capability of moving and digging tons of earth in a single day. He likes to be a leader and treats the younger members of the Pack with respect.
Oliver's exact basis is unknown and appears to be a freelance design.
Oliver is painted brown with a pale green panel on his back and his number painted on him in red. Oliver has the cap rim of a builder's hat between his forehead and cab windows.
- Season 6 - Jack Jumps In and A Friend in Need
- Jack and the Sodor Construction Company - A Visit from Thomas, Jack Owns Up (cameo), On Site with Thomas, Percy's Scary Tale (cameo), A Happy Day for Percy, A Tale for Thomas, Thomas and the Moles (does not speak), Percy Helps Out (cameo), The Tortoise and the Hare, Thomas' Trusty Friends, Alfie Has Kittens (does not speak) and Mud Glorious Mud
- Season 20 - Mucking About
- Season 21 - The Fastest Red Engine on Sodor (cameo) and A Shed for Edward (cameo)
- 2008 - The Great Discovery
- 2015 - Sodor's Legend of the Lost Treasure
- 2016 - The Great Race (fantasy)
- 2006 - Jack
- 2007 - Alfie
- 2011 - Alfie the Excavator and Jack the Front Loader
- 2015 - A Really Useful Engine, Sodor's Legend of the Lost Treasure: Sticker Activity Book, Sodor's Legend of the Lost Treasure: The Movie Storybook (cameo) and Thomas' New Friend
- Tim Whitnall (UK/US; Sodor's Legend of the Lost Treasure onwards)
- Ryō Horikawa (Japan; sixth season only)
- Yuta Odagaki (Japan; Sodor's Legend of the Lost Treasure onwards)
- Igor Cruz (Latin America; Sodor's Legend of the Lost Treasure onwards)
- Matthias Klimsa (Germany; Sodor's Legend of the Lost Treasure onwards)
- An early concept art design for Oliver reveals his name was originally meant to be Buster.
- When Oliver returned in full CGI, his smaller wheels appear to have slightly increased in size.
- Tim Whitnall gives Oliver an Irish accent.
- Oliver is the first character to share his name with another character in the television series, and the second to do so in the entire Thomas franchise, the first being Bert and Iron Bert.
- TrackMaster (discontinued)
- Capsule Plarail (discontinued)
- Wooden Railway (paired with Oliver the GWR engine)
- Adventures (Paired with Jack, Thomas, and a Truck)