- Lithium metal batteries
- Lithium nickel manganese cobalt oxide
- Lithium nitrate
- Lithium nitride
- Lithium oxide
- Lithium perchlorate
- Lithium peroxide
- Lithium polymer battery
- Lithium soap
- Lithium stearate
- Lithium sulfate
- Lithium sulfide
- Lithium tantalate
- Lithium titanate
- Lithium triborate
- Lithium triflate
- Lithium tungstate
- Lithium-6
- Lithium-air battery
- Lithium-ion battery
- Lithium-ion capacitor
- Lithium-titanate battery
- Lithocholic acid
- Lithology
- Lithophile
- Lithosphere
- Lithosphere-asthenosphere boundary
- Lithospheric mantle
- Lithostratigraphic
- Lithostratigraphy
- Litmus
- Litracon
- Litter
- Little Ice Age
- Little finger
- Little's Law
- Littrow angle
- Littrow prism
- Litz wire
- Live
- Live birth
- Live steam
- Liver
- Liver abscess
- Liver biopsy
- Liver cancer
- Liver disease
- Liver failure
- Liver fluke
- Liver function tests
- Liver injury
- Liver metastasis
- Liver sinusoid
- Liver support system
- Liver transplant
- Liver transplantation
- Liver tumors
- Living Building Challenge
- Living hinge
- Living labs
- Living polymerization
- Living streets
- Living systems
- Lixiviants
- Lizardite
- Lloyd's algorithm
- Lo-nox burner
- LoRa
- Load balancing
- Load bank
- Load cells
- Load duration curve
- Load factor
- Load line
- Load management
- Load profile
- Load pull
- Load testing
- Load-bearing walls
- Loader
- Loaders
- Loading dock
- Loam
- Lobe pump
- Lobectomy
- Lobes
- Lobular carcinoma
- Local anesthesia
- Local bus
- Local consistency
- Local coordinates
- Local diffeomorphism
- Local differential privacy
- Local field potential
- Local food
- Local independence
- Local loop
- Local optima
- Local oscillator
- Local reference frame
- Local regression
- Local search
- Local structure
- Local tangent space alignment
- Local time
- Local truncation error
- Local variable
- Locale
- Localhost
- Locality-sensitive hashing
- Localization
- Localized surface plasmon
- Locally compact
- Locally compact abelian groups
- Locally compact group
- Locally compact space
- Locally constant
- Locally convex
- Locally convex topological vector space
- Locally finite
- Locally flat
- Locally integrable
- Locally integrable functions
- Locate
- Location intelligence
- Location parameter
- Location-allocation
- Loci
- Lock-free
- Lock-in amplifier
- Locked-in syndrome
- Locks
- Locoweed
- Locus coeruleus
- Locust bean gum
- Loellingite
- Loess
- Lofting
- Log analysis
- Log files
- Log probability
- Log reduction
- Log-concave
- Log-linear models
- Log-normal distribution
- Log-periodic antenna
- Log4j
- Logarithm of a matrix
- Logarithmic
- Logarithmic decrement