When Thomas Osmond Griffiths was born on 28 November 1859, in Tenby, Pembrokeshire, Wales, United Kingdom, his father, Thomas Henry Griffiths, was 25 and his mother, Mary Thomas, was 25. He married Sarah Louisa M Stoddard on 19 October 1887, in Cache, Utah, United States. They were the parents of at least 3 sons and 3 daughters. He lived in Grant, Washington, United States in 1930 and Tacoma, Pierce, Washington, United States in 1940. He died on 26 March 1949, in Puyallup, Pierce, Washington, United States, at the age of 89, and was buried in Oakwood Hill Cemetery, Tacoma, Pierce, Washington, United States.