In enzymology, an alkylhalidase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are bromochloromethane and H<sub>2</sub>O, whereas its 3 products are formaldehyde, bromide, and chloride.
This enzyme belongs to the family of hydrolases, specifically those acting on halide bonds in carbon-halide compounds. The systematic name of this enzyme class is alkyl-halide halidohydrolase. Other names in common use include halogenase, haloalkane halidohydrolase, and haloalkane dehalogenase.