José Guillermo (J. G.) Hay was a nature conservationist in New South Wales and Western Australia.
Hay owned and developed large landholdings around Lawson in the Blue Mountains during the 1880s and 1890s; a number of properties and features there are named in his honour.
[1] Hay came to Australia from California, and in 1879, purchased 121.4 hectares of land near the Blue Mountain railway station.
Hay developed real estate around Lawson, and lived in a landmark building known as "The Sanatorium" (later known as "The Palace") and was involved in various community improvement activities in the district.
In 1906, Hay presented a paper to the West Australian Natural History Society titled The visit of Charles Fraser (the Colonial Botanist of New South Wales) to the Swan River in 1827, with his opinion on the suitableness of the district for a settlement; together with copious notes by J. G. Hay; to which is added The Journal of H.M.S.