Firefighters were called to the blaze in a flat in Whitedalehead Road, Whitburn, at around 19:40 on Thursday.
A spokeswoman for the Scottish Fire and Rescue Service said they gave four casualties oxygen therapy.
The patients - who also included a man and a woman - were then taken to St John's Hospital in Livingston by ambulance.
They fire was extinguished and the scene was made safe within an hour.
Two children were among four people taken to hospital following a fire in West Lothian.