Origins

The Guppy surname seems to have originated in Dorset and Somerset, England, although its early instances were spelled in a variety of interesting ways.

Woodland Manor in Mere, Wiltshire, once known as Gupphey or Guphay or Gapphey, was largely built by Joan, daughter of John Gupphey, c. 1360 but the walls and foundations date from the 11th century

In Dorset there was a village called Guppy (formerly Guppehegh) and the name still appears on modern maps although no one lives in Guppy now.

"The earliest known bearer of the name is Nicholas de Gupehegh (Somerset, 1253/4). Most, if not all, present-day bearers of the name seem to descend from a certain William Guppy of Chardstock, Dorset, who in 1497 was fined forty shillings for his alleged part in the rebellion of Perkin Warbeck." [Note that this is not likely true: there are a large group of Guppys descended from a group of Guppys from Wooton Fitzpaine, Dorset, who moved to Halstock, also in Dorset, in the early 1500s and who were very prolific. There is no known connection to William of Chardstock.]
-- A Dictionary of Surnames, Patrick Hanks and Flavia Hodges, Oxford University Press, 1988

"For nearly four centuries, in fact as far back as the parish registers enable us to trace the name, the principal home of the Guppys has been in Dorset, close to the Somerset and Devon borders, as shown by the wills in Somerset House; several families of well-to-do yoeman bearing this name resided in Halstock, South Perrott, Cheddington, and Frampton, during the 16th and 17th centuries. Pickyeate, Pykeyeate, or Picket, in South Perrott, was the residence of a family of Guppy or Guppie as far back as the reign of Elizabeth, and the name has since been frequent in the South Perrott registers until within the last twenty years.

"From Dorset the name extended into the surrounding counties of Somerset, Devon, and Wales, in the last two of which it is now very rare or extinct. A family of Guppy resided at Farway, Devon, from the beginning of the 17th century (perhaps earlier) until a generation ago: to this stock belong the Guppys of Sidbury castle in the early part of this century. Somerset has long known the name.

"Among the martyrs of the Monmouth rebellion in 1685 were William and Justinian Guppy of Taunton, who were transported to Barbadoes, and died both of them on the voyage; whilst Roger Guppy was excecuted at Bridgewater
(Hetton's American Emigrants; Western Martyrology).

"A gentle family of Guppy resided in Chard last century, and to the Somersetshire Guppys belonged the founder of the present engineering firm at Naples [Italy -- this is Thomas Richard Guppy, born 1797]. It is remarkable that after nearly 400 years the name yet lingers around its old Dorset home in Halstock and South Perrott; a few of the name are still to be found in Somerset. The extinct Wiltshire family is referred to under that county."
from Homes of Family Names in Great Britain by Henry Brougham Guppy, London, 1890

There has been a persistant theory that the Guppy surname originated in Italy, as Guy Pigli. This family moved to France and, in the 17th century, came to England amongst the persecuted Huguenots, where their name was Anglicized to Gupil and later to Guppy. I would not like to say that there are no Guppys who can trace their name thusly, but I have no such records.

You can find information about over 5,000 Guppys and their relatives at Don and Jeanne Ross's Guppy Research file which contains all the Guppys born more than 100 years ago that they know of. It contains many disconnected families as well as some large trees. Some data is speculative, all should be treated as requiring verification. This is a work in progress