Bion of Abdera (Greek: Βίων ὁ Ἀβδηρίτης) was a Greek mathematician of Abdera, Thrace, and a pupil of Democritus. He wrote both in the Ionic and Attic dialects, and was the first who said that there were some parts of the earth in which it was night for 6 months, while the remaining 6 months were one uninterrupted day.