A member of the public alerted the beach office after discovering the reptile on the rocks at Splash Point.
It took several men to safely lift and remove the turtle, which was approximately 1.5 metres long.
Senior foreshore inspector Graham Cherrett said: “I think it is a loggerhead, which are known in these waters and it must have been at least 200lbs.
“I’ve never seen one this big washed-up on the beach.
“It will now be taken into storage by our cleansing team and the Natural History Museum will be contacted, who will conduct a post-mortem.”
Reader Andrew Cole, 40, of Park Road, Worthing, took a picture of the turtle and reported it to The Herald.
He said: “I was about to take a panoramic shot of Worthing from Splash Point and I saw it on the rocks.
“It was so big, and was absolutely amazing. I’ve never seen anything like it in Worthing.”