H
- Hadrian - Hadrian's Wall and Hadrian's Wall Path
- Amber Hagerman, abducted child - AMBER Alert
- Otto Hahn — hahnium, chemical element. This element name is not accepted by IUPAC. See element naming controversy
- Edwin Hall — Hall effect
- Edmond Halley — Halley's Comet
- Hugh Halligan — Halligan bar
- Laurens Hammond — Hammond Organ
- Hamo, a 6th century Saxon settler and landowner — Hampshire
- John Hancock, signatory of the US Declaration of Independence — John Hancock, a signature
- Elliot Handler and Harold "Matt" Matson — Mattel
- William Hanna and Joseph Barbera — Hanna-Barbera Productions
- Gerhard Armauer Hansen — Hansen's disease
- William Harley and Arthur Davidson — Harley-Davidson
- Alexis Hartmann — Hartmann's solution, given via the IV route to patients
- Douglas Hartree — Hartree energy
- Gerry Harvey and Ian Norman — Harvey Norman
- Hashimoto Hakaru — Hashimoto's thyroiditis
- Hassan-i-Sabah, leader of the murderous Hashshashin cult — assassin from hassansin (this etymology is disputed)
- Victor Hasselblad — Hasselblad, medium format photographic camera system
- Stephen Hawking — Hawking radiation
- Paul Hawkins — Hawk-Eye tracking system used in cricket and other sports
- Frank Hawthorne — mineral Frankhawthorneite
- Oliver Heaviside and Arthur Edwin Kennelly — Kennelly–Heaviside layer
- Henry Heimlich - Heimlich Maneuver
- Joseph Henry — henry, unit of inductance
- William Henry — Henry's law
- Milton S. Hershey - Hershey Company
- Heinrich Rudolf Hertz — hertz, unit of frequency
- Ejnar Hertzsprung and Henry Norris Russell — Hertzsprung-Russell diagram
- William Hewlett and David Packard — founders, Hewlett-Packard
- Edward C. Heyde — Heyde's syndrome
- Miguel Hidalgo — Hidalgo
- David Hilbert — Hilbert's program
- Eugen von Hippel — Von Hippel-Lindau disease
- Harald Hirschsprung, Danish physician — Hirschsprung's disease
- Paul von Hindenburg — after whom the Hindenburg airship was named
- Thomas Hobbes, 17th century philosopher — Hobbes from "Calvin and Hobbes" comic strip
- Thomas Hobson (1544–1630), stable manager in England — Hobson's choice, an only apparently free choice that is no choice at all
- Thomas Hodgkin — Hodgkin's disease, Non-Hodgkin's lymphoma
- Homer, father of Matt Groening, creator of The Simpsons — Homer Simpson, character in The Simpsons animated TV series
- Sherlock Holmes - anyone who solves a mystery or a difficult problem, based on the fictional character by Sir Arthur Conan Doyle
- Soichiro Honda — founder, Honda
- Mark Honeywell — founder, Honeywell
- Robin Hood, English folk hero — Robin of the Batman series
- Robert Hooke — Hooke's law
- William Henry Hoover (1849–1932) — The Hoover Company; in British English, the verb "hoover" means "to vacuum a floor" while the noun is the vacuum cleaner. The word "hoover" has also come to mean anything that is sucked up at a great rate ("They hoovered their way through the banquet").
- August Horch — founder of Audi (audi is Latin for horch. It means listen in English)
- Leslie Hore-Belisha - Belisha beacon
- James Horlick and William Horlick — founded the company Horlicks in 1873
- Frank Hornby - inventor of Meccano, Hornby and Hornby-Dublo train sets, and Dinky Toys
- William Howe (1803–1852) — Howe truss bridges
- Hroc, an ancient landowner ("Hroc's fortress" + shire) — Roxburghshire
- Henry Hudson - Hudson Bay, Hudson River, Hudson Strait
- Howard Hughes — Hughes Aircraft company, Howard Hughes Medical Institute, Hughes Airwest airlines, Hughes Glomar Explorer ship
- Howard R. Hughes, Sr. — Hughes Tool Company, Baker Hughes company
- John Huss (Czech: Jan Hus) — Hussite, Czechoslovak Hussite Church
Read more about this topic: List Of Eponyms (A-K)