China 
Africa 
- High-temperature corrosion
- High-temperature electrolysis
- High-temperature engineering test reactor
- High-temperature gas-cooled reactor
- High-temperature superconductivity
- High-throughput computing
- High-voltage cable
- High-voltage switchgear
- High-water mark
- High-κ dielectric
- Highcharts
- Higher alkanes
- Higher education accreditation
- Higher power
- Higher-order functions
- Higher-order logic
- Higher-order modulation
- Higher-order statistics
- Highest weight
- Highly charged ions
- Highly elliptical orbits
- Highly ionized
- Highway engineering
- Hilbert Curve
- Hilbert Transform
- Hilbert matrix
- Hilbert space
- Hilbert spectral analysis
- Hilbert spectrum
- Hilbert's program
- Hildebrand solubility parameter
- Hill Cipher
- Hill climbing
- Hill equation
- Hill reaction
- Hill yield criterion
- Hill-start assist
- Hillclimbing
- Hills
- Hilsenhoff Biotic Index
- Hilum
- Hindgut
- Hindgut fermentation
- Hindlimb
- Hindsight bias
- Hinge joints
- Hinge loss
- Hinges
- Hip
- Hip arthroscopy
- Hip bone
- Hip examination
- Hip fractures
- Hip protectors
- Hip replacement
- Hip resurfacing
- Hippocampal sclerosis
- Hippocampus
- Hippocratic Oath
- Hippuric acid
- Hirsutism
- Hirudin
- His-tag
- Histamine
- Histamine receptors
- Histaminergic
- Histatin
- Histidine kinase
- Histocompatibility
- Histogenesis
- Histogram
- Histogram equalization
- Histogram matching
- Histogram of oriented gradients
- Histology
- Histone H1
- Histone acetyltransferase
- Histone deacetylase
- Histone deacetylase inhibitor
- Histone methylation
- Histone methyltransferase
- Histone variants
- Histones
- Histopathology
- Histoplasmosis
- Historical geology
- Hit rate
- Hit-or-miss transform
- Hits algorithm
- Hives
- Hobbing
- Hodge star operator
- Hodgkin lymphoma
- Hodograph
- Hoek-Brown failure criterion
- Hoffmann kiln
- Hofmeister series
- Hogging and sagging
- Hoist
- Holding
- Holding cost
- Holds
- Hole saw
- Holes
- Holistic management
- Hollandite
- Hollow cathodes
- Hollow fiber bioreactor
- Hollow fiber membrane
- Hollow-cathode lamps
- Holmium
- Holmium oxide
- Holmquistite
- Holocene
- Holocene Climatic Optimum
- Holographic data storage
- Holographic display
- Holographic gratings
- Holographic interferometry
- Holographic principle
- Hololens
- Hololens 2
- Holonomic constraints
- Holons
- Holter monitor
- Home automation
- Home computer
- Home directory
- Home energy rating
- Home hemodialysis
- Home network
- Home page
- HomeKit
- HomePod
- Homeobox
- Homeostasis
- Homeoviscous adaptation
- Homing endonucleases
- Homo economicus
- Homoarginine
- Homochirality
- Homoclinic connection
- Homoclinic orbit
- Homocysteine
- Homodyne detection
- Homogeneity
- Homogeneous
- Homogeneous broadening
- Homogeneous catalysis
- Homogeneous coordinates