John Scotney, of Cromwell Way, Market Deeping travelled from Land's End to John O'Groats, supported for the final 300 miles by his son Daniel, 30, and raised money for Sue Ryder Cancer Care Home.
John, who is retired, began his trek from Land's End on Monday, July 28, He had taken a train to Penzance before cycling 10 miles to his starting point. Along the way he stopped at youth hostels as he cycled 50 miles each day.
When John reached Glasgow he met his son Daniel, of Peterborough, and they completed the final stretch together.
He said: "It was quite lonely cycling on my own but you cope. I met many people along the way who were taking the same route as me."
When the pair saw the John O'Groats sign on the horizon John admits it provoked a few emotions.
"The joy of seeing the sign Welcome to John O'Groats was a momentous and joyful occasion," he added.
Father and son then took a short cycle to Wick, before boarding a train home. It took John a total of 21 days cycling and he said his legs were like jelly after completing the challenge.