3C 273 (273rd object of the Third Cambridge Catalog of Radio Sources (3C), published in 1959) is a quasar located in the constellation Virgo. It is notable as being first quasar discovered and one of the few visible with amateur equipment.

A few years after its discovery it was in 1963 determined that the quasar had substantial redshift, placing it several billion light-years away.

The quasar lays at a distance of 2.44 Gly and has, as one of the most luminous quasars known with an absolute magnitude of -26.7, a measured mass of 886 ą 187 million solar masses.

The jet can clearly be seen and has been estimated to have a length of ~200 kly.