James Alfred Wanklyn (18 February 1834 – 19 July 1906) was a nineteenth-century English analytical chemist who is remembered today chiefly for his "ammonia method" of determining water quality and for his fierce arguments with those, such as Edward Frankland, who opposed him over matters related to water analysis.

He was born in Ashton-under-Lyne on 18 February 1834 the son of Thomas Wanklyn and his wife, Ann Dakeyne, both members of the Moravian Brethren.

In 1860 he was elected a Fellow of the Royal Society of Edinburgh his proposer being Lyon Playfair.

[3] In 1877 he returned to London to lecture in Chemistry and physics at St George's Hospital but resigned in 1880.

[3] He died at home, 6 Derby Villas in New Malden in Surrey on 19 July 1906.