Valerius Cordus (18 February 1515 – 25 September 1544) was a German physician, botanist and pharmacologist who authored the first pharmacopoeia North of the Alps and one of the most celebrated herbals in history.

He is also widely credited with developing a method for synthesizing ether (which he called by the Latin name oleum dulci vitrioli, or "sweet oil of vitriol").

In 1515, Valerius Cordus was born either in the city of Erfurt in what is today Thuringia, or somewhere in the westwardly adjacent state of Hesse.

His father, Euricius Cordus (born Heinrich Ritze, 1486–1535), was an educated physician and an ardent Lutheran convert.

Among the research outlined in the lectures were the results of his own systematic observations of many of the same plants described by Pedanius Dioscorides in the 1st century CE.

In 1540 Cordus discovered and described a revolutionary technique for synthesizing ether, which involved adding sulfuric acid to ethyl alcohol.