Eight-year-old, Harrison Morrell, started the 200-mile challenge at the beginning of April, to raise £500 for the National Autistic Society.
Harrison, who has autism, set out on the challenge to prove that 'nothing should hold you back' and has been running 6.6 miles each day to clock up 200 miles over the month.
He finished his last few miles by running into his school, Richard Taylor, on Bilton Lane, during playtime today, April 30.
Harrison's Headteacher, Andrew Symonds said: "I think we all think its absolute incredible - when Harrison's parents told me that he was planning to run 200 miles for the National Autistic Society, we couldn't believe he was going to run that far.
"Harrison has huge amounts of energy, the staff are thrilled and amazed and the children think he's absolutely amazing as well."
Harrison, who is also an avid footballer, was inspired to start fundraising when he completed a triathlon for the National Autistic Society (NAS) last year.
But Mr Symonds said that Harrison's 200-mile challenge could be his greatest achievement to date.
He added: "I think his classmates are all supportive of everything that Harrison does, obviously he's a wonderful footballer as well, we've heard about his triathlons and we've celebrated those successes. I think this is his greatest achievement so far though, to be able to run 200 miles is just an amazing feat.
"When he arrived into school they went wild, they cheered him, they clapped him on and patted him on the back, and it was fantastic to see that when he finished his 200th mile he went straight off to play with them and was running around the playground, so I certainly think he's inspired several people."
Harrison has smashed his original fundraising target, raising £715 for the NAS.