Solomon III (died 919) is the Bishop of Constance from 890 to his death.

In 885, the Emperor Charles III makes him archchancellor of the Empire, for Konstanz is at this time the greatest diocese in Swabia, which had been Charles' original kingdom and is still his home most of the time.

As well as bishop, he is also abbot of Reichenau and Saint Gall, immensely powerful abbeys in Swabia and the Rhineland.

Solomon founds a church in honor of Saint Magnus at Saint Gall.