Joseph, 21, has raised £350,000 for his local football club's disability sports project. He ran 6.2 miles twice a day through European cities before ending in his hometown Altrincham, Greater Manchester.
Joseph had run little more than a mile before beginning his "No Limits" challenge in Amsterdam.
But he said: "I was so happy to finish and see all of my friends in the crowd. I really struggled with the heat but with the help of extra malt loaf and 80s rock music, I was able to make it."
Dad Phil, 57, said: "Joseph is a big swimmer - he won gold at the Down's Syndrome world championships. We thought we would go for a bigger challenge."
Donate to Joseph's efforts at gofundme.com/f/josephs-challenge-no-limits
