He ran to raise awareness of bullying of young people, with the money collected to be shared between charities Stonewall and Kidscape.
Ben set himself the gruelling challenge of running round the UK to raise awareness of bullying after he was picked on at school for being gay.
Throughout the 10,506.2 miles challenge, he has battled injuries including a long-standing spinal problem and pain in his kneecaps, heels and shins.
The runner has also given 101 motivational talks to schools, colleges and universities to raise awareness of bullying. He has gone through 22 pairs of trainers and burned more than 2.5m calories.
Over 200 people gathered to cheer the 34-year-old over the line, as well as 372 runners following on, including 30 primary school children joining Ben for the final mile.
An emotional Mr Smith thanked his parents, partner and team for their support.
“I think I’m in a bit of shock,” he said. “I can’t believe we have done this.
“Without every single person who has taken part, we wouldn’t be where we are now and I can’t thank you enough. I am sure the charities will thank you.”
But Ben, who raised £250,000 for anti-bullying charities, has to carry on running as he is now addicted to endorphins.