is a Latin phrase that refers to indispensable and essential action, condition, or ingredient.
Sine qua non may also refer to: "Sine Qua Non" (Battlestar Galactica), an episode of the sci-fi TV series Battlestar Galactica Sine Qua Non (wine), a California cult wine producer "Sinequanon", a song by Hybrid appearing on the 1999 album Wide Angle