Fluoromethane, also known as methyl fluoride, Freon 41, Halocarbon-41 and HFC-41, is a non-toxic, liquefiable, and flammable gas at standard temperature and pressure. It is made of carbon, hydrogen, and fluorine. The name stems from the fact that it is methane (CH4) with a fluorine atom substituted for one of the hydrogen atoms.

The compound is the lowest mass member of the hydrofluorocarbon (HFC) family, compounds which contain only hydrogen, fluorine, and carbon. These are related to the Chlorofluorocarbon (CFC)s, but since they do not contain chlorine, are not destructive to the ozone layer.

It is used in the manufacture of semiconductor and electronic products. In the presence of an RF field fluoromethane will dissociate into fluoride ions that selectively etch silicon compound films (reactive-ion etching).

Fluoromethane has an agreeable ether-like odor and is also narcotic in high concentrations. Fluoromethane is highly flammable and burns in air with evolution of highly toxic hydrogen fluoride. The flame is colorless, similar to alcohol.Bond energy of C-F is 552 kJ/mol and its length is 0.139 nm (typically 0.14 nm). Its molecular geometry is tetrahedral.

Its specific heat capacity is Cp = 38.171 J.mol−1.K−1 at 25 °C. Critical point of fluoromethane is at 44.9 °C (318.1 K) and 6.280 MPa.