William Humfrey (also Humphrey or Humphreys) (died 1579) was a goldsmith and Assay Master to Queen Elizabeth I of England.
He had a patent from the Queen for the mining of various ores and the extraction of metals from their ores. These rights were transferred to the Company of Mineral and Battery Works in which he was a leading shareholder. In 1569 (or shortly after) he built one of the earliest lead smeltmills using white coal in England at Beauchief.