An E&M Horsburgh coach was reported ablaze at around 8.30am on Monday westbound on the A71 near the Wilderness Roundabout, Bellsquarry.
School pupils exited safely with the driver of the bus by the time emergency services arrived on the scene.
Police, fire and ambulance were in attendance and the incident was cleared by 10.30am.
A replacement bus picked up the pupils shortly afterwards and they were taken to school.
Photographs show considerable fire damage to the back and middle of the coach.
A Police Scotland spokeswoman said there were no injuries.
A spokeswoman for Pumpherston-based E&M Horsburgh said: “Everybody was evacuated from the bus safely. We’re trying to establish what happened.”
Asked if the singledecker had passed required tests, she added: “Of course it had, it wouldn’t have been on the road if it hadn’t.”
A spokesman for the Scottish Fire and Rescue Service said: “The Scottish Fire and Rescue Service was alerted at 8.31am on Monday, February 11 to reports of a bus on fire in Livingston.
“Operations Control mobilised three fire engines to Bellsquarry Road where firefighters extinguished the fire.
“There were no casualties.
“Crews left the scene after ensuring the area was made safe.”
A spokesperson for West Lothian Council said: “We understand from the operator that the bus driver noticed smoke from the rear of the vehicle and pulled over as a precaution allowing the pupils to depart the bus unharmed. Pupils were picked up shortly afterwards by another bus and taken to school.
“We’ve asked the bus operator to provide us with further details. Council officers visited the site this morning and will work with the operator to progress with an investigation.”
A temporary diversion remains in place near the scene of the incident.
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