Qoppa (uppercase Ϙ, lowercase ϙ) is an obsolete letter of the Greek alphabet and has a numeric value of 90. It has been attested in early Aeolic and Boeotian scripts, while the sound [kʷ] is attested in the Linear B syllabary. Greek dropped the sound, a labial-velar plosive, it presented in the post-Mycenaean era, and the letter survived for a few more centuries in certain dialects before becoming altogether extinct by pre-Classical times. There are two very different glyphs for qoppa: "archaic qoppa" (Ϙ ϙ) used to write words and "numeric qoppa" (Ϟ ϟ) used in modern Greek legal documentation.
Qoppa was originally borrowed from the Phoenicians, who had /q/ (a voiceless uvular plosive) in their language. It was later imported into the Etruscan alphabet, and through this eventually into the Latin alphabet, in its current form Q. It was also adopted into the early Cyrillic alphabet, as koppa (Ҁ, ҁ).