Bas (Greek: Βᾶς; c. 397 BC – 326) was the first independent ruler of Bithynia. He ruled for fifty years, from 376 to 326 BC, and died at the age of 71.

Bas succeeded his father Boteiras, and was himself succeeded by his own son Zipoetes I.

Bas defeated Calas, a general of Alexander the Great, and maintained the independence of Bithynia.^[1]

• Smith, William (editor); Dictionary of Greek and Roman Biography and Mythology, "Bas", Boston, (1867)
•  This article incorporates text from a publication now in the public domain: Smith, William, ed. (1870). "Bas". Dictionary of Greek and Roman Biography and Mythology. Vol. 1. p. 465.