Sir John Henry Greville Smyth, 1st Baronet (2 January 1836 – 27 September 1901) was an English naturalist and collector of natural history specimens.
He is best known for his large private collection of mammals, birds, and insects kept at his stately home of Ashton Court in Bristol.
He was educated at Eton College and Christ Church, Oxford, and on the death of his grandmother in 1852 succeeded to the Ashton Court estate.
He used this sizable income to fund tours across the British Empire and beyond (India, Egypt, Algeria, Australia, New Zealand, Jamaica, South America, and the United States of America, as well as extensive travel across Europe), where he hunted mammals and birds, and collected a vast number of birds' eggs.
Greville Smyth had built up such a large collection of specimens that in 1884 he commissioned the architect Charles Edward Davis to create a museum in his home.