Leech was educated at Eton College and Trinity Hall, Cambridge.
They went to live in Hurdcott House, Barford St Martin, Wiltshire.
[2] Leech's collections from China, Japan and Kashmir are in the Natural History Museum, London, along with specimens from Morocco, the Canary Islands and Madeira.
He wrote British Pyralides (1886) and Butterflies from China, Japan and Corea in three volumes (1892–1894).
[3] He is buried in St Edith's churchyard, Baverstock, Salisbury, Wiltshire, UK.