Douglas Smallwood (54) and his son Jimmy (24) completed the 192 mile walk from St Bee's Head in the Lake District in 13 days.
The father and son team hope the challenge, where they followed in the footsteps of celebrated walker Alfred Wainwright, raises more than £5,000 to help children with diabetes.
Diabetes UK runs special care events for some of the 20,000 youngsters in the UK with Type 1 diabetes, where they can take part in sporting activities and receive advice on how to manage the condition.
However, children who need to use insulin pumps are not always able to attend the care events because of a lack of specialist nurses trained in pump therapy. Mr Smallwood said: "For children with diabetes, attending the Diabetes UK care events can be life-changing, so it's a shame not all children have been able to take part.
"Hopefully that will improve when I raise more than £5,000 to pay for the training of 15 new nurses in insulin pump therapy."
The duo have gathered around £4,500 in sponsorship so far.
"I am very pleased to have raised this much already," Mr Smallwood said. "Being diagnosed with diabetes is a a big thing for young people who will have the condition for the rest of their lives and will need to learn to look after it. This funding will benefit them, with more understanding of the condition."
The pair felt weary after their efforts, but enjoyed a visit to Whitby, as they are big fans of the town.
Highlights of the trip were the local people that they met, the scenery, and the chance to get to spend time together.
Mr Smallwood said: "It was very good for me to get to do this with my son. "I don't get to spend too much time with him, so it was very special."
To donate to the cause, visit Douglas Smallwood's challenge page at www.diabeteschallenge.org.uk/smallwood-walk