William Henry Griffith Thomas (2 January 1861 – 2 June 1924) was an Anglican cleric and scholar from the English-Welsh border country.

Then 20 years old, he worked for his stepfather's younger brother, William Charles, who was a watch dial maker.

The speech was delivered to the Presbyterian Social Union in Philadelphia in January 1921 and caused a great deal of debate among the churches and mission boards in North America.

There is certainly no evidence that Thomas personally initiated the Bible Union in China, but his speeches in China during summer missionaries retreat had the effect of significantly intensifying the conservatives' negative sentiment toward modernism in the field and prompting them to take public action.

More recently, Griffith Thomas has been quoted in the current science-versus-religion debate by the theologian Alister McGrath in his argument with the scientist Richard Dawkins over the issue of whether or not religious faith is based on evidence.