The ex-midfielder was given the all-clear of stomach cancer in November 2021, following a 10-month battle with the illness.
Thomas planned a sponsored walk up Snowdon as a way of giving back to the NHS, and set out to raise £20,000 in collaboration with NHS Wales charity, Blue Sky North Wales.
The 67-year-old was joined by members of the team who performed his life-saving surgery at Wrexham's Maelor Hospital, as well as close family, friends and local supporters in celebrating his huge milestone.
The money raised will help other patients who are being cared for at the hospital, specifically in the Upper G.