Walter Wilson Froggatt (13 June 1858 – 18 March 1937) was an Australian economic entomologist.
Froggatt was born in Melbourne, Victoria, the son of George Wilson Froggatt, an English architect, and his wife Caroline, daughter of Giacomo Chiosso, who came from a noble Italian family. As a child Froggatt, who was delicate, was encouraged by his mother to find interests in the open air and at an early age began collecting insects. The family having moved to Bendigo, Victoria he was educated at the Corporate High School, Sandhurst (Bendigo), and on leaving school spent four years on the land. In 1880 he went to a goldfield near Milparinka, New South Wales, and then worked his way northward and through Queensland to Mackay, Herberton, Cairns and other parts of the colony. Wherever he went he kept up his collecting of insects.
In 1883 Froggatt returned to Bendigo, worked with his father on a lease near Mount Hope, and around this time contacted Charles French Senior and Baron von Mueller. It was partly through Mueller's good offices that Froggatt was appointed entomologist and assistant zoologist to the expedition sent to New Guinea in 1885 by the Royal Geographical Society of New South Wales. The party left in June 1885 and returned on 4 December 1885. Early in 1886 Froggatt was engaged by William Macleay as a collector. He at once proceeded to North Queensland and formed large collections. In March 1887 he went to north-west Australia, began collecting in the Derby district and later in the more inland country. He returned to Derby after severe attacks of fever and then went to the Barrier Range to recover his health. Returning to the coast he took steamer on 22 February 1888 for Fremantle and thence to Sydney, where he arrived on 31 March 1888. Froggatt then went to England at the invitation of an uncle and gained much experience in European museums and universities. On his return he worked at the Macleay museum until it was transferred to the university, and in 1889 was appointed assistant and collector at the Sydney technological museum. From 1890 the first of a long series of papers by him was published in the Proceedings of the Linnean Society of New South Wales. Froggatt was a founder in 1891 and later president for a record eleven years of the Naturalists' Society of New South Wales. In 1896 he was appointed government entomologist to the agricultural department of New South Wales.