William Buckler (13 September 1814 in Newport – 9 January 1884 in Lumley near Emsworth) was an English painter and entomologist who specialized in Lepidoptera.
He is the illustrator and (along with John Hellins (entomologist)) author of The Larvae of the British Butterflies and Moths edited by Henry Tibbats Stainton and George Taylor Porritt which was published by the Ray Society.
The 164 plates of hand-coloured illustrations took thirty years to complete.
His collection is in the Natural History Museum.