Sir John Kyffin Williams, OBE, RA (9 May 1918 – 1 September 2006) was a Welsh landscape painter who lived at Pwllfanogl, Llanfairpwll, on the Island of Anglesey.

[1] Williams enrolled at London's Slade School of Fine Art in 1941 (relocated to Oxford during the war), gaining prizes for portraiture at the end of both his second and third years.

[4] Wales never left his consciousness or imagination, as he would return home in holidays, take his study sketches back to London and complete his canvasses.

In 1968 he won a Winston Churchill Fellowship to study and paint in Y Wladfa, the Welsh settlement in Patagonia,[1] South America.

Never having married, Williams died, without heirs, on 1 September 2006, aged 88, at St Tysilio Nursing Home on Anglesey.

Later in 2006, the Welsh singer and Manic Street Preachers frontman James Dean Bradfield included a track called "Which Way to Kyffin", dedicated to Williams, on his album The Great Western.

[13] His last passport, on show in the Oriel Ynys Môn gallery at Llangefni, 2004–2014, has the name Sir John Williams.

[15] In June 2018, he was the subject of a 50-minute BBC Television documentary, Kyffin Williams: The Man Who Painted Wales, presented by Josie d'Arby.

[4] Williams' former home, "Min y Môr", a Grade II listed cottage overlooking the Menai Strait, is now rented out for holidays.