Six-month-old black and white cat, Hugo, was found on Sunday morning hanging from a pice of twine from the bridge over the M62 at Ferrybridge near junction 33.
The police were called, along with the RSPCA, and his owner was informed after he was found to have be microchipped.
Owner Lorna Taylor said: “I last saw him on Saturday night. I was pulling sticky buds out of his fur.
“I had only had him for a short time but it’s absolutely devastating to think about what has happened to him.
“He was a very bold cat and he would have fought his corner. Whoever did this must be covered in scratches.”
It is thought the incident must have happened some time between about 9pm on Saturday and 10.15am on Sunday.
Anyone with any details is being asked to call the RSPCA appeal line on 0300 123 8018 and ask to leave a message for Inspector Hutton.