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 rate of reaction
• 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
• Social inhibition, a conditioned fear reaction to social marginalization or isolation.