3C 273 was one of the first quasars discovered in 1963. It remains one of the brightest and best studied quasars. It is located approximately 3 billion light years from Earth and radiates energy equivalent to 1014 times the luminosity of the Sun. 3C 273 plays a key role in understanding the nature of quasars as powered by accretion disks around supermassive black holes. It continues to be intensely observed across the electromagnetic spectrum to better understand the physics occurring in these energetic and distant cosmic objects.