| Actor/Actress | Region | Role(s) | Notes |
| Joseph May[1] |
US | Thomas | From The Adventure Begins until series 24 |
| John Hasler[2] | UK |
| UK/US | Rheneas | Series 20 only |
| Jonathan Broadbent[3] | UK/US | William "Bill", Benjamin "Ben" and the First Slip Coach | |
| Teresa Gallagher[4] |
UK | Emily, Lady Hatt (Season 13, "Day of the Diesels" and Season 15), Mavis (Season 13–16), The Duchess of Boxford, Stephen Hatt ("Diesel's Special Delivery"), Bridget Hatt, Bridget Hatt's friends, the teacher, the laundry lady, little boy in light white and light blue stripes shirt and red shorts, some children, the school children, little girl in the red dress, the blonde-hair girl, and the blonde-hair boy | |
| US | A blond-haired girl | "Very Important Sheep" |
| A blonde-haired boy | "Very Important Sheep" only |
| UK/US | Belle, Frieda, Gina (The Great Race only), Mavis (FQC 1), Annie, Clarabel, Judy, Cassia (Big World! Big Adventures! only), The Duchess of Boxford ("Percy's Lucky Day" only), Lady Hatt ("The Afternoon Tea Express" only and Season 21 onwards), the teacher (Season 18 only), the ginger-hair boy, the shouting little boy, the lady with the big hat, some passengers, the Knapford Station speaker ("The Adventure Begins"), some children ("The Adventure Begins" onwards), the school children ("Lost Property"), Stephen Hatt, Bridget Hatt, the lady in the blue dress, the barrow fan ("Reds vs. Blues" and "Useful Railway"), Albert's wife ("Thomas the Babysitter" and "Unscheduled Stops"), the lady in spring green dress, the female puppet show entertainer, little girl in the turquoise dress with pink flowers, the lady in the white dress and gray vest, the lady in the white shirt, light brown skirt and hat, the lady in the grayish white shirt, blackish gray skirt, and white pearl necklace, the chubby little boy in dark green shirt and dark gray shorts, the lady in the yellow dress and hat, The Blonde Haired Girl, The Lady in Red and Indigo Hat and White Dress with Gray lines, Female Passengers, Madeleine's Mother, Brenda, and The Sodor Rangers | |
| Rasmus Hardiker[5] | UK/US | William "Bill", Philip and the Troublesome Trucks ("The Fastest Red Engine on Sodor" only) | |
| UK | Monty[broken anchor] | |
| Steven Kynman[6] | UK | Porter, Jack[broken anchor], Racing Car #3 and the Dock Manager ("Tale of the Brave" only) | |
| US | Charlie | "The Great Race" only |
| Butch | Series 17 to 24. |
| UK/US | Montague "Duck", Ryan (series 20 onwards), Dart (Season 17 onwards), Paxton ("Blue Mountain Mystery" onwards), Peter Sam, "The Third Slip Coach", a workman (Journey Beyond Sodor), a railway inspector (Season 17), the bird watcher ("Who's Geoffrey?"), and a Child | |
| Joe Mills |
| Donald (series 18—series 19), Douglas,[7] Oliver, Toad, the Welsh bird watcher ("Thomas and the Emergency Cable"), a Knapford Station yard workman ("Toad and the Whale"), and a Passenger ("Confusion Without Delay") | [8] |
| Tracy-Ann Oberman |
UK/US | Daisy | Series 20 through Series 24 |
| Nigel Pilkington[9] | UK | Percy and Trevor | Series 19 through Series 24 |
| Christopher Ragland | US |
| UK/US | The Troublesome Trucks ("The Adventure Begins" onwards), Racing Car #4, some Cowboys, and a Passenger | |
| John Schwab |
US | Stanley | Series 20 only, excluding "Saving Time"[citation needed] |
| Rob Rackstraw[10] |
UK | Toby | |
| UK/US |
James (UK: "Tit for Tat"–series 24/US: The Adventure Begins–series 24), Stanley, Owen, Donald (Series 20 onwards), The Small Controller, Bradford, Hugo, Big Mickey, Bernie, Professor Friederich, The Thin Clergyman, Monty, Thief 1 |
|
| Kerry Shale[11] | UK/US | Diesel (UK: Series 13–24/US: Series 19–24) | |
| US | Sir Topham Hatt (Hero of the Rails-series 18), Henry, Gordon, James (Hero of the Rails-series 18), Kevin | |
| Martin Sherman | US | Thomas, Percy, Diesel (King of the Railway–series 18) | Hero of the Rails through series 18[12] |
| Ben Small[13] | UK/US | Rheneas, Flynn (series 17), Owen and Troublesome Trucks | Series 16 through series 18 |
| UK | Thomas, Toby and Ferdinand | Hero of the Rails through series 18 |
| US | Stanley and Charlie | Series 15 through series 18 |
| Keith Wickham[14] | UK | Edward, Henry, Gordon, James ("Hero of the Rails"-"The Great Race"; excluding "Tit for Tat"), Percy (Hero of the Rails-Sodor's Legend of the Lost Treasure; excluding Series 19), Whiff, Dash, Harold, The Thin Controller, the railway coal inspector, the man at the fire, the Wellsworth Station Worker, the Fat Controller's Assistant, some Workmen, some Passengers, Gator's Driver, and a Steamworks Workman | |
| UK/US | Harvey, Glynn, Salty, Den, Norman, Stafford, Skarloey, Sir Handel, Arlesdale Bert, Bertie, Captain, Sir Topham Hatt/The Fat Controller (UK; Hero of the Rails-series 24/US; The Adventure Begins-series 24), Dowager Hatt, Sir Lowham Hatt, Lord Callan, the photographer ("Wild Water Rescue"), a Railway Inspector, the Great Composer, the Maron Station Speaker, the Wellsworth Stationmaster, Thomas' Guard, the Grumpy Passenger, Father Christmas, the Groundsman, Tom Tipper, Gordon's driver (The Adventure Begins), James' guard (The Adventure Begins), a Knapford station worker (The Adventure Begins), some Workmen, some Signalmen, the dock manager ("Who's Geoffrey?" only), a Sodor search & rescue centre worker ("Toad and the Whale"), the policemen, a Diver (Sodor's Legend of the Lost Treasure), Some Passengers, Albert ("Thomas the Babysitter"), Mr. Bubbles, the Welsh Bird Watcher ("Sidney Sings and Three Steam Engines Gruff"), one of Dowager Hatt's friends ("Best Engine Ever" and "Sidney Sings"), the Museum Manager, the Male Puppet show Entertainer, Willie, Franz, the Station Announcer, a Child ("Gordon Gets the Giggles"), The Mainland Stationmaster, Thomas' Driver, Thomas' Fireman, and the Elderly Man. | |
| Matt Wilkinson[15] | UK | Spencer, Stanley, Charlie, Bash, Scruff, Rocky, Cranky, Carter, Butch[broken anchor] (Season 16 onwards), Kevin, Tony, Stephen Hatt ("Thomas and the Runaway Kite"), Farmer McColl, the Duke of Boxford, the photographer (series 16), the Maithwaite stationmaster, Farmer Trotter, the Knapford stationmaster, the bird watcher ("Henry's Good Deeds"), the blond-haired boy ("Merry Misty Island"), the dock manager, a railway inspector, some dock workers, the island inspector, the Sodor search & rescue centre manager, the Blue Mountain Quarry workman, the zoo keeper and the man with the hat | |
| UK/US | Ben, Diesel 10, Winston, Rusty, Merrick, Captain Joe, some workmen, Male Passengers, and The Man in Blueish Grey Shirt, Whitish Cream shorts, and Aquamarine hat | |
|
