In music, the submediant is the sixth degree () of the diatonic scale, the lower mediant—halfway between the tonic and the subdominant ("lower dominant").[1][2] In the movable do solfège system, the submediant note is sung as la in major, as fa in minor. It is occasionally called superdominant,[3] as the degree above the dominant. This is its normal name (sus-dominante) in French.

The scale and submediant triad in the C major (top) and C minor (bottom) Scale.

The triad formed on the submediant note is the submediant chord. In Roman numeral analysis, the submediant chord is typically symbolized by the Roman numeral "VI" if it is major and by "vi" if it is minor.

The term submediant may also refer to a relationship of musical keys. For example, relative to the key of C major, the key of A minor is the submediant. In a major key, the submediant key is the relative minor and has the same notes as the original major key. Modulation (change of key) to the submediant is relatively rare, compared with modulation to the dominant in a major key or modulation to the mediant in a minor key.