d-Phenothrin (d-trans-Phenothrin, Phenothrine, Phenoxythrin, C₂₃H₂₆O₃, CAS#26002-80-2) is a synthetic pyrethroid that kills adult fleas and ticks. It has also been used to kill head lice in humans. d-Phenothrin is used as a component of aerosol insecticides for domestic use. Phenothrin is often used with methoprene, an insect growth regulator that interrupts the insect's biological life cycle by killing the eggs.

d-Phenothrin is primarily used to kill fleas and ticks. It is also used to kill head lice in humans, but studies conducting in Paris, France and the United Kingdom have shown widespread resistance to phenothrin.