This chapter presents new, annotated translations of the testimonia and fragments of Pytheas of Massalia (active c.330–c.320 BC), arranged as 32 extracts. (Translations of passages from Strabo are adapted with permission from the work of D. W. Roller.) The chapter introduction observes the difficulty of assessing Pytheas accurately, given the dominance of Strabo’s testimony, to which alone we owe our knowledge of the criticisms of the Massaliote by Polybios, perhaps arising from class prejudice; but defends his reputation, as recent scholarship has tended to do, and relates him to contemporary activity in Aristotle’s Peripatos (Lyceum). Although Pytheas owed much to earlier Massaliote voyagers, he is an important and original figure, particularly for his application of mathematical astronomy to questions of latitude and the tides. A new map shows the key points in his travels around northern Atlantic coasts and the British Isles, including the possible locations of Thule.