NOS Alive (formerly Optimus Alive) is an annual music and arts festival held in the Algés riverside, close to Lisbon, in Portugal. It is organized since 2007 by the Portuguese live entertainment company Everything is New. Its naming sponsor is telecommunications company NOS (previously named Optimus).
It takes place during the second week of July and lasts 3 or 4 days. It currently has six stages, including a stage dedicated to fado music and a stage dedicated to stand-up comedy.