Τ

Tau (; uppercase Τ, lowercase τ or ; ) is the nineteenth letter of the Greek alphabet, representing the voiceless dental or alveolar plosive . In the system of Greek numerals, it has a value of 300.

The name in English is pronounced or , and in Greek it is . This is because the pronunciation of the combination of Greek letters αυ can have the pronunciation of either , or , depending on what follows and if a diaeresis is present on the second vowel in Greek orthography.