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 its activity.
- 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
- Lateral inhibition, a mechanism by which neurons are able to determine the origin of a stimulus
- 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.