| C/2014 Q3 (Borisov) | |
| Discoverer: | Gennadiy Borisov 0.3 m astrograph (L51) |
| Discovery Date: | 22 August 2014 |
| Epoch: | 9 December 2014 |
| Perihelion: | 1.6474 au (q) |
| Aphelion: | 55.111 au |
| Eccentricity: | 0.94196 |
| Period: | 146 years (epoch 2050) |
| Inclination: | 89.949° |
| Last P: | 19 November 2014 |
| Next P: | ~2160 |
C/2014 Q3 (Borisov) is a periodic comet discovered at apparent magnitude 17 on 22 August 2014 by amateur astronomer Gennadiy Borisov using a 0.3m (01feet) astrograph. It is the third comet discovered by Borisov. The comet is best viewed from the northern hemisphere.
The comet was expected to reach about magnitude ~11 near perihelion (closest approach to the Sun), but brightened to around magnitude 10. By 8 November 2014, the comet had a declination of +83 and was circumpolar from the northern hemisphere. The comet came to perihelion on 19 November 2014 at a distance of 1.65 au from the Sun.
Before entering the planetary region (epoch 1950), C/2014 Q3 had an orbital period of 148 years. After leaving the planetary region (epoch 2050), it has an orbital period of 146 years.