H
- Philipp Matthäus Hahn – mechanical calculator
- Eldon C. Hall – Apollo Guidance Computer
- Wendy Hall
- Joseph Halpern
- Richard Hamming – Hamming code, founder of the Association for Computing Machinery
- Jiawei Han – Data mining
- Juris Hartmanis – computational complexity theory
- Johan Håstad – computational complexity theory
- Les Hatton – software failure and vulnerabilities
- He Jifeng – provably correct systems
- Martin Hellman – encryption
- Gernot Heiser – Development of L4 and founder of OK Labs
- James Hendler – Semantic Web
- John L. Hennessy – computer architecture
- Andrew Herbert
- Danny Hillis – Connection Machine
- Geoffrey Hinton
- Julia B. Hirschberg – Computational Linguistics
- C. A. R. Hoare – Logic, rigor, Communicating sequential processes (CSP)
- John Henry Holland – genetic algorithms
- Herman Hollerith (1860–1929) – invented recording of data on a machine readable medium, using punched cards
- John Hopcroft – compilers
- Admiral Grace Hopper (1906–1992) – developed early compilers: FLOW-Matic, COBOL; worked on UNIVAC; gave speeches on computer history, where when gave out nano-seconds
- Eric Horvitz – artificial intelligence
- Alston Householder
- David A. Huffman (1925–1999) – Huffman coding, used in data compression.
- John Hughes – structuring computations with arrows; QuickCheck randomized program testing framework; Haskell programming language design.
- A. E. Hugo – parallel computing on heterogeneous multicore architectures
- Watts Humphrey (1927–2010) – Personal Software Process (PSP), Software quality, Team Software Process (TSP)
Read more about this topic: List Of Computer Scientists