Oliver was built at Swindon works in 1934, and was based on a 14XX. He worked on a branchline on the Great Western Railway (British Railways after 1948) with two of his brothers named Clarence and Paul, and his brake van, Toad, until the decline of steam in the 1950s. He was withdrawn from service, and sent for scrap in 1967. However, he, Toad, and a coach named Isabel escaped the scrap yard, and were on the run to Sodor until he was caught by Splatter and Dodge after running out of coal. He was taken to the Barrow-in-Furness Scrapyard, awaiting the end until one night, an engine called Douglas from the NWR came with a goods train. Oliver convinced him to rescue him, and the two engines snuck out, making it look like Douglas was taking him for scrap. He was successfully brought to Sodor, and was snuck into Crovan's Gate to get repaired but word soon spread to the Fat Controller. However, the Fat Controller, who desired another steam engine, was very pleased, and made Oliver the number 11 on his railway. Oliver pulled passenger trains mainly until 1966, when he learned about trucks. His first encounter did not go well. He became conceited after the engines admiration of him, and ordered the trucks around which made them push him into the turntable well. He was sent to the works again, and when he returned, the trucks, led by a truck known as S.C.Ruffey (Scruffey), sang rude songs about him. However, when Scruffey tried holding back on Oliver, Oliver pulled so hard that he fell apart. Now, the trucks fear Oliver greatly.
Oliver's 2006 SI3D model was used in Episodes II and V. His 2010 model from Skarloey the Great's Model was used in Episode IV, and How the Diesel Stole Christmas onwards. His RWS model is used in NWR Origins.
Oliver is a Great Western Railway 14xx 0-4-2T. A total of 75 were built between 1932 and 1936. Four remain in preservation today.
When he first arrived in 1967, he became full of himself, which led to the trucks tricking him, and pushing him in the turntable. Now, Oliver is a very hard worker, but can be unhappy about his jobs, which can lead to depression and angry outbursts. However, he takes no nonsense from anyone and will show them who's the boss, like when he pulled Scruffey to pieces. But generally, Oliver is very kind, and willing to help.
- Gordon Goes Swimming (cameo)
- Bill and Ben the Brave Brothers of Brendam (cameo)
- Mike Takes the Road (cameo)
- Engine Unknown (mentioned)
- Gordon Pops In (does not speak)
- How the Diesel Stole Christmas (part 2 and 3 only)
- The Search for Smudger (cameo)
- The Most Famous Engine (cameo in part 1)
Oliver also appeared in a deleted scene of Haunted Henry.
- KnapfordProductions: How the Diesel Stole Christmas-Episode XI
- The Peel Godred Branch: NWR Origins-Present
- Thomas1Edward2Henry3: Oliver's Tiny Tale
Oliver was introduced in the third season episode Escape. He appeared in every Season until Season 8. (He only made cameos in Season 6). He then appeared in Seasons 12 and 18-20. He is voiced by Joe Mills in the US, and UK.
- Oliver was the last member of the NWR 11 to be introduced, and the only one in the third season. Ironically, he was also the last engine to have a first speaking role of the NWR 11 in TEOS. He did not speak until How the Diesel Stole Christmas.
- Thomas1Edward2Henry3 always preferred Oliver over Duck. Oliver had more exciting adventures and did not go on and on about the Great Western Way.
- Oliver is the only member of the NWR 11 not to have an SI3D 2010 or 2012 model released.