Edward Lhuyd (pronounced [ˈɬuɪd]; usually rewritten as Llwyd in recent times) (1660 – 30 June 1709) was a Welsh naturalist, botanist, linguist, geographer and antiquary. He is also known by the Latinized form of his name, Eduardus Luidius.
Lhuyd was born in Loppington, Shropshire, the illegitimate son of Edward Lloyd of Llanforda, Oswestry and Bridget Pryse of Llansantffraid, near Talybont, Ceredigion, and was a pupil and later a master at Oswestry Grammar School. His family belonged to the gentry of south-west Wales; though well-established, his family was not well-off, and his father experimented with agriculture and industry in a manner that brought him into contact with the new science of the day. Lhuyd attended grammar school in Oswestry and went up to Jesus College, Oxford in 1682, but dropped out before his graduation. In 1684, he was appointed assistant to Robert Plot, the Keeper of the Ashmolean Museum and replaced him as Keeper in 1690; he held this post until 1709.
Whilst employed by the Ashmolean he travelled extensively. A visit to Snowdonia in 1688 allowed him to construct for John Ray's Synopsis Methodica Stirpium Britannicorum a list of flora local to that region. After 1697, Lhuyd visited every county in Wales, and then travelled to Scotland, Ireland, Cornwall, and Brittany and the Isle of Man. In 1699, with financial aid from his friend Isaac Newton, he published Lithophylacii Britannici Ichnographia, a catalogue of fossils collected from places around England, mostly Oxford, and now held in the Ashmolean.