Thionyl fluoride is the inorganic compound with the formula SOF2.

This colourless gas is mainly of theoretical interest, but it is a product of the degradation of sulfur hexafluoride, an insulator in electrical equipment.

The molecule adopts a distorted pyramidal structure, with Cs symmetry.

[3][page needed] Thionyl fluoride can be produced by the reaction of thionyl chloride with fluoride sources such as antimony trifluoride.

The related derivative, sulfur tetrafluoride is however useful for that purpose.