Farmer Collett is a farmer who regularly appears in the magazines. He is good friends with Jem Cole and owns a bull named Lord Harry, several horses and other animals. He owns his own farm and a red tractor.
He is old-fashioned and often remembers the "good old days". He regularly travels to the village on one of his horses along a bridleway. The bridleway was split in two when Thomas' Branch Line was constructed. This was later solved 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 Farmer Collett is a good artist as well as a farmer.
One winter, Farmer Collett's sheep escaped and ended up at the engine sheds, searching for food. Percy soon returned them.
Farmer 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 season episode, Baa! is Farmer Collett in the television series; however it is actually Jem Cole.
- According to a magazine poster, Farmer Collett is the farmer with the sheep in the eighth season episode, Chickens to School.