Rail operator First Great Western has apologised to passengers after a train driver forgot to stop at Didcot Parkway on Wednesday night.
Dozens of passengers were affected by the mistake which meant they had to wait 30 minutes at Swindon station before returning to Didcot.
The company blamed "driver error" but added that the driver was checked after the incident and deemed fit for duty.
An investigation into the matter is being carried out.
Christopher Proctor, 37, from Abingdon, was one of the passengers on the 1815 Paddington to Swansea service.
He said: "I was surprised when the train went shooting through Didcot Parkway because it's a scheduled stop on the service.
"It went through at full tilt and then slowed down when I guess the driver realised what they'd done.
"We heard a pre-recorded message over the Tannoy along the lines of 'could the train manager please contact the driver'.
"We then had a very sheepish train manager apologise over the Tannoy, citing 'unforeseen circumstances' as the reason for not making the scheduled stop."
Mr Proctor estimated that up to 150 passengers were affected.
A First Great Western spokesman said: "We apologise for any inconvenience caused to customers who wished to get off the train at Didcot.
"The incident was down to a driver error and the driver was met at Swindon, where he was checked and deemed fit for duty.
"We do take this sort of thing seriously and a full investigation will be carried out, which will take up to 28 days to complete."