Jack Humphrey, 20, was driving home from work at the William Withering pub in Wellington in the early hours when he says the creature leapt in front of his car.
He said: "I was driving past the new houses in Trench Lock, where the roofing centre is, when it ran across the road. It was huge.
"It must have been three times the size of a fox and it was jet black.
"Its tail was thin and long, it was definitely a panther."
Previous sightings of a big cat in Telford took place in 2008, when Shropshire Star reader Sarah Leeder said she came across the animal while she was walking on the trail near Apley Woods.
She said: "It was too big for a domestic cat and did not look like a dog. There was nobody near the animal at the time."
The body of a dead big cat was also found along the riverbank on the Severn Way in Shrewsbury in 2009 by local paramedic Terry Meagre, although at the time the British Big Cat Society said despite its size it appeared to be a normal, domestic cat.
A big black cat has also been spotted near Stafford Park, Lightmoor, Broseley and Woodside, as well as stalking along the Silkin Way which runs through the borough.
In November 2006 a big cat sighting by a policeman prompted officers into a late-night search near The White Horse pub in Dawley, Telford. But a search found no trace of it.
Mr Humphrey said: "Now I've seen it I definitely believe it.
"It leapt three times, much higher than a fox can. Then it jumped straight into a bush."
Since the sighting at around 2.30am last Thursday night, Mr Humphrey says he will be keeping an eye out for the panther in future.
He said: "I went that way on Friday to see if I could see it again.
"I got a taxi the other day and the driver swore that he had seen the same thing but said no-one believes him.
"Another lad at work thinks I'm lying but someone wrote on my Facebook page saying he believes me and he won't be driving that way again."
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