Reverend William Leigh Williamson Eyre (17 March 1841 – 25 October 1914) was an English mycologist and naturalist.

He was educated for the merchant navy and worked as a seaman until his religious convictions led him to enter Lichfield Theological College to study for Holy Orders.

He was ordained in 1865 and became curate of a number of English parishes before being appointed, in 1875, rector of Swarraton and vicar of Northington, Hampshire, where he remained for the rest of his life.

He was a member of the Hampshire Field Club and took an interest in local plants, especially species of the genus Rubus, and in land and freshwater molluscs.

[2][3] His collections of new and interesting fungal species, mostly made in the Swarraton area, were for the most part passed on to and described by contemporary mycologists at the Royal Botanic Gardens, Kew, namely M.C.