| C/1915 C1 (Mellish) | |
| Discoverer: | John E. Mellish |
| Discovery Date: | 10 February 1915 |
| Designations: | 1915a 1915 II |
| Epoch: | 30 June 1915 (JD 2420678.5) |
| Observation Arc: | 376 days (1.03 years) |
| Obs: | 94 |
| Perihelion: | 1.0053 AU |
| Semimajor: | –3,663.395 AU |
| Eccentricity: | 1.00027 |
| Inclination: | 54.792° |
| Asc Node: | 73.453° |
| Arg Peri: | 247.782° |
| Earth Moid: | 0.3339 AU |
| Jupiter Moid: | 0.9970 AU |
| M1: | 7.7 |
| Last P: | 17 July 1915 |
C/1915 C1 is one of five comets discovered by American astronomer John E. Mellish. It is a hyperbolic comet that reached perihelion on July 17, 1915. However, just two months earlier, Edward E. Barnard had reported the comet had splitted into three distinct objects in May 12, later increasing to four by May 24. In addition, it is thought that this comet was the parent body of the June Lyrids meteor shower, which was first discovered in 1966.