Spurius Cassius S. f. S. n. Viscellinus or Vecellinus (d. 485 BCE) is one of the most distinguished men of the early Roman Republic.

He is three times consul, and celebrates two triumphs.

He is the first magister equitum, and the author of the first agrarian law.

The year following his last consulship, he is accused of aiming at regal power, and is put to death by the patricians.

From his filiation, "S. f. S. n.", we know that Cassius' father and grandfather were both named Spurius.

According to one tradition, his father was still living and hale at the time of his death.

If this were the case, it would be difficult to place Cassius' birth much earlier than 540 or 535 BCE.

Cassius also left behind him three sons, whose names have not been preserved.

It is believed that the Cassii Viscellini were patricians, although the later members of the gens occurring in history were all plebeian.

The historian Niebuhr suggests that Cassius' sons may have been expelled by the patricians from their order, or that they or their descendants may have voluntarily passed over to the plebeians, because the patricians had shed the blood of their father.