Józef Sylwester Sosnowski (died 31 December 1783), of the Nałęcz coat-of-arms, was a Polish-Lithuanian magnate — Voivode of Smolensk (from 1771) and Połock (from 1781), Grand Notary of Lithuania (1754), Field Notary of Lithuania (1764–71), Field Hetman of Lithuania (1775–80), a delegate to the Convocation Sejm of 1764, and Marshall of the Electoral Sejm of 1764.
