Farmer Collett is a farmer who regularly appears in magazine stories. He is good friends with Jem Cole and owns a bull named Lord Harry, several horses, and other animals. He and his wife own a farm, a red tractor, and a green tractor.
Collett is old-fashioned and often reminisces about the "good old days". He regularly travels to the village on one of his horses along a bridleway, which was split in two when Thomas' Branch Line was constructed. The gap was later bridged when the Fat Controller purchased a cheap scrap turntable from the Mainland to be made into a bridge to cross Thomas' line.
Farmer Collett once decorated an old oil tank to make it look like Thomas in an effort to get a rare bluebird to move out of Thomas' funnel. The trick worked and the bluebird now happily resides in a chimney pot on the old oil tank. Thomas named the oil tank, Bluebird. After drawing the face on the oil tank, Thomas remarks that Collett is a good artist as well as a farmer.
When Collett's sheep escaped and ended up at the engine sheds, searching for food, Percy returned them to the farm.
Collett once got stuck in a ford with his horse and cart and two boxes of plums. Terence had to come to his rescue.
Collett has worked as a gardener at Dingley Hall where he cut some bushes into the shapes of animals which scared the engines.
- The magazine story, Summer Fun! suggests that the man holding the pumpkin in the fifth series episode, Baa! is Farmer Collett; however it is actually Jem Cole.
- For a while it was unknown who the sheep farmer was but from a magazine poster, it turned out to be Farmer Collett.