John Hasler (born in Barking, London, England, on 21 April 1974) is an English actor and voice actor who joined the English voice cast of Thomas & Friends in The Adventure Begins. He took over the roles of Thomas and Rheneas from Ben Small.
Hasler is best known for his appearance as T-Shirt in the children's TV series T-Bag. Other credits include "Gnomeo and Juliet" (animated by Arc Productions), "Toot the Tiny Tugboat", "Teenage Fairytale Dropouts", "Go Jetters", "The Legends of Treasure Island", and two of HiT Entertainment's other shows; "Mike the Knight" and "Fireman Sam".
- Thomas (The Adventure Begins onwards)
- Never Overlook a Little Engine (performed)
- We Wish You a Merry Christmas (performed)
- Will You Won't You (performed)
- Streamlining (performed)
- You Can Only Be You (performed)
- Be Who You Are, and Go Far (performed)
- Somebody Has to be the Favourite (performed)
- Who's Thomas? (performed)
- The Hottest Place in Town (performed)
- I Want To Go Home (performed solo)
- The Most Important Thing is Being Friends (performed)
- Where in the World is Thomas? (performed)
- Wake Up (performed)
- We're Friends (performed)
- Sometimes You Make a Friend (performed solo)
- Don't Stop (performed)
- He and his family attended the Blue Carpet premiere events of Sodor's Legend of the Lost Treasure on 12 July 2015, The Great Race on 22 May 2016 and Big World! Big Adventures! on 07 July 2018.
- As a child actor, Hasler co-starred in Breakout along with Simon Nash, who voiced Ten Cents in TUGS.
- Since 2018 when Thomas became the new narrator, Hasler has been the only UK cast member to date not to narrate an episode for the US dub.