Inhibitor or inhibition may refer to:
- Corrosion inhibitor, a substance that decreases the rate of metal oxidation
- Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity
- Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotransmitter
- Inhibition of return, a feature of attention
- Inhibition Theory, a theory pertaining to the performance of a mental task
- Inhibitors (Revelation Space), machines in Alastair Reynolds's Revelation Space novels
- Latent inhibition, a term used in classical conditioning
- Lateral inhibition, a neural mechanism that increases contrast between active and (neighbouring) inactive neurons
- Memory inhibition, processes that suppress or interfere with specific memories
- Reaction inhibitor, a substance that prevents or decreases the rate of a chemical reaction
- Sexual inhibition, reservations relating to sexual practices
- Social inhibition, a conditioned fear reaction to social marginalization or isolation
- "Inhibitions", a 2008 single by Swedish band Alcazar
- Inhibitory postsynaptic potential, a synaptic potential that decreases the firing of a neuron