Watcyn Thomas (16 January 1906 – 10 August 1977) was a Welsh rugby union player who captained Wales in the early 1930s.
A teacher by profession, he moved to St Helens to teach at Cowley Grammar School in 1929, and played rugby for Waterloo and Lancashire, captaining Lancashire to the championship in 1934–35.
After Llanelli's victory against the touring New Zealand Maoris, he won his first cap for Wales against England in 1927.
In 1936 he moved to Birmingham to teach at King Edward VI School Aston,[2] and died in that city in 1977.
He was the first Welsh man to be president of the English Schools Rugby Football Union.