| Name | Number | Description | Based on |
| Skarloey | SR 01 | A red narrow gauge saddle tank engine and is one of the oldest engines on the Skarloey Railway. He is voiced by Keith Wickham. | Talyllyn |
| Rheneas | SR 02 | A vermillion narrow gauge well tank engine and the Skarloey Railway's second engine. Rheneas has the nickname "Gallant Old Engine", after saving the railway from closure. He is voiced by Ben Small and later John Hasler. | Dolgoch |
| Sir Handel | SR/MSR 03 | A blue narrow gauge saddle tank engine originally of the Mid Sodor Railway, where he was originally named "Falcon". He now works on the Skarloey Railway. He is voiced by Keith Wickham. | Sir Haydn |
| Peter Sam | SR/MSR 04 | A green narrow gauge saddle tank engine originally of the Mid Sodor Railway, where he was originally named "Stuart". He now works on the Skarloey Railway. Following an accident with some slate trucks, Peter Sam lost his funnel and was fitted with a special funnel as a replacement. He is voiced by Steven Kynmann. | Edward Thomas |
| Rusty | SR 05 | A kind and friendly orange little narrow gauge diesel engine who carries out maintenance work and odd jobs on the Skarloey Railway. He is voiced by Matt Wilkinson. | Midlander |
| Duncan | SR 06 | A grumpy and bad-tempered yellow Scottish narrow gauge well tank engine on the Skarloey Railway. He came to the Skarloey Railway as a spare engine after Peter Sam's accident with some slate trucks. He is voiced by Tom Stourton. | Douglas |
| Freddie | SR 07 | An old narrow gauge tank engine on the Skarloey Railway. He was originally planned to be voiced by Bob Golding. | Russell |
| Duke | SR 08 | An orange-brown narrow gauge tank-tender engine who is widely respected and considered a hero amongst all the engines. He is also one of the oldest engines on Sodor, having been ordered by and named after "His Grace" the Duke of Sodor for the Mid Sodor Railway. He was left in his old shed after his railway closed down, but was eventually rediscovered and put to work on the Skarloey Railway. | Festiniog Railway 0-4-0TT |
| ' | SR 09 | An olive green narrow gauge tank engine who used to work on the Mid Sodor Railway. He was later turned into a generator due to his tendency to misbehave and derail frequently. | Dolgoch |
| ' | SR 10 | An old narrow gauge tank-tender engine who worked at the mines. His real name is "The Old Warrior", but was nicknamed "Bertram" because of his bravery. He lived on a remote part of the Island that was once rarely visited. His railway has since been restored as a fairground and he now pulls passenger trains on it. | Festiniog Railway 0-4-0TT |
| ' | | A blue double-ended engine and conjoined twins. Mighty is the "older" of the two and is distinguished by a small flick of hair. Mac is the "younger" half and is distinguished his youthful features, round nose, and freckled cheeks. Despite the opposing personalities of the two ends, they are technically one engine. | Fairlie locomotive |
| ' | | A legendary yellow narrow gauge saddle tank engine with a magic lamp hung upon his funnel. | Sir Haydn |
| Victor | | A dark red narrow gauge tank engine from Cuba who works at the Sodor Steamworks with his assistant, Kevin. | Minaz Co., No. 1173 |
| Luke | SR 22 | A green Irish narrow gauge saddle tank engine who works primarily at the Blue Mountain Quarry on the Skarloey Railway. | 'Peter Pan', a 'Wren' class locomotive |
| Millie | | A light blue narrow gauge engine from France who helps run Sir Robert Norramby's Estate Railway at Ulfstead Castle. Her duties include assisting the Groundskeeper and taking visitors on tours of the estate. For this, she has her own set of open-topped coaches. | Decauville No. 8069 Tabamar |