Prof William Hallowes Miller FRS HFRSE LLD DCL (6 April 1801 – 20 May 1880) was a Welsh mineralogist and laid the foundations of modern crystallography.

Miller was born in 1801 at Velindre near Llandovery, Carmarthenshire, South Wales.

[3] He was educated at St John's College, Cambridge, where he graduated in 1826 as fifth wrangler.

For a few years Miller was occupied as a college tutor and during this time he published treatises on hydrostatics and hydrodynamics.

[5] Miller also gave special attention to crystallography, and at 31 years old, on the resignation of William Whewell he succeeded in 1832 to the professorship of mineralogy, a post he held until 1870.