C/2013 R1 (Lovejoy) is a long-period comet discovered on 7 September 2013 by Terry Lovejoy using a 0.2-meter (8 in)Schmidt–Cassegrain telescope. It is the fourth comet discovered by Terry Lovejoy. C/2013 R1 crossed the celestial equator on 14 October 2013, becoming a better Northern Hemisphere object.
By 1 November 2013, the comet was visible to the naked eye near the Beehive Cluster (M44), about halfway between Jupiter and Regulus. It became more impressive than comet ISON. In binoculars, the comet has the appearance of a green, unresolved globular cluster.
C/2013 R1 made its closest approach to Earth on 19 November 2013 at a distance of 0.3967 AU (59,350,000 km; 36,880,000 mi), and reached an apparent magnitude of about 4.5. On 27 November 2013 the comet was in the constellation of Canes Venatici, near the bottom of the handle of the Big Dipper. From 28 November until 4 December 2013, the comet was in the constellation Boötes. On 1 December 2013 it passed the star Beta Boötis. From 4 December until 12 December 2013, the comet was in the constellation Corona Borealis.
From 12 December until 14 January 2014, the comet was in the constellation Hercules. On 14 December 2013, it passed the star Zeta Herculis. The comet came to perihelion (closest approach to the Sun) on 22 December 2013 at a distance of 0.81 AU (121,000,000 km; 75,000,000 mi) from the Sun. At perihelion, the comet had an elongation of 51 degrees from the Sun. By September 2014, the comet had fainted to magnitude 18.