The adventurous black-and-white cat was found on Monday morning by alarmed workers who immediately called the Scottish SPCA.
The lorry had been conducting house clearances in Kirknewton and East Calder and it's thought the cat must have either climbed into one of the rubbish bags or the lorry to investigate.
The cat, who was found wearing a sparkly black collar with a bell and tag attached, was uninjured in the journey. After a vet examination he was found to be in good condition, indicating he is well-loved at home.
There were no details on the cat's collar and he was not microchipped so there was no way of contacting his owner.
SSPCA ambulance driver Emma Phillips collected the cat. She said: "Cats are inquisitive so he may have decided to explore the contents of the lorry. He's a lovely lad and we're sure his owner is out there somewhere and missing him terribly."
The Scottish SPCA is appealing to his owner to call the Animal Helpline on 03000 999 999. He is currently being cared for at Lamond Vet Clinic in Livingston.