John William Brazier (23 September 1842 – 20 August 1930) was a malacologist from Australia.
He was born to Captain John Brazier and his wife Mary nee McMillan.
His father commanded whaling vessels out of Sydney, Australia, and during his voyages he collected sea shells as a hobby.
In 1865 John Brazier junior accompanied Julius Brenchley on the voyage of H.M.S.
After several other shell collecting expeditions in Australasia he joined William John Macleay 's 1875 expedition in the Chevert to New Guinea via the Great Barrier Reef.