Sodium trimethylsiloxide is an organosilicon compound with the formula NaOSi(CH<sub>3</sub>)<sub>3</sub>. It is the sodium salt of the conjugate base derived from trimethylsilanol. A white solid, its molecular structure consists of a cluster with Na-O-Na linkages on the basis of closely related compounds.
The salt is used to prepare trimethylsiloxide complexes by salt metathesis. Trimethylsiloxide is a lipophilic pseudohalide.
It is a source of oxide dianion.