- Hartebeesthoek Radio Astronomy Observatory
- Hartford
- Hartford Convention
- Hart inversor
- hartite
- Hartkemeier
- Hartley
- Hartley 2 Comet
- Hartley formula
- Hartley oscillator
- Hartley test
- Hartley transform
- Hartline-Ratliff model
- Hartman
- Hartman flow
- Hartmanis
- Hartmann
- Hartmann-Cornu formula
- Hartmann crater
- Hartmann diaphragm
- Hartmann dispersion formula
- Hartmann flow
- Hartmann method
- Hartmann number
- Hartmann test