Bulk metallic glasses are commonly produced by the rapid cooling of liquid alloys. They have emerged over the past decade as a novel class of materials, with attractive properties and technological promise. The bulk metallic glasses so far produced contain three or more component elements. These complex compositions are necessary to frustrate the crystallization of the liquid melt on cooling, but can also lead to phase separation, which is detrimental to the thermal and mechanical properties of metallic glasses. Here we report, using X-ray diffraction measurements, the formation of a bulk metallic glass from elemental zirconium at high static pressures and low temperatures (relative to its melting temperature at atmospheric pressure). Amorphous zirconium can be recovered at ambient conditions and demonstrates a superior thermal stability compared to amorphous alloys, which could lead to new high-temperature applications of amorphous metals.