| C/1961 R1 (Humason) | |
| Discoverer: | Milton L. Humason |
| Discovery Date: | 1 September 1961 |
| Designations: | 1961e 1962 VIII |
| Epoch: | 12 May 1963 (JD 2438161.5) |
| Observation Arc: | 1,517 days (4.15 years) |
| Obs: | 80 |
| Perihelion: | 2.1334 AU |
| Aphelion: | 408.706 AU |
| Semimajor: | 205.419 AU |
| Eccentricity: | 0.98961 |
| Period: | 2883 years (barycentric inbound) 2516 years (barycentric outbound) |
| Inclination: | 153.278° |
| Asc Node: | 155.439° |
| Arg Peri: | 233.562° |
| Tjup: | –1.588 |
| Earth Moid: | 1.2247 AU |
| Jupiter Moid: | 1.0725 AU |
| Last P: | 10 December 1962 |
| M1: | 1.5–3.5 |
| M2: | 10.1 |
| Dimensions: | 30−41 km |
Comet Humason, formally designated C/1961 R1 (a.k.a. 1962 VIII and 1961e), was a non-periodic comet discovered by Milton L. Humason on September 1, 1961. Its perihelion was well beyond the orbit of Mars, at 2.133 AU. The outbound orbital period is about 2,516 years. The diameter of its comet nucleus is estimated at 30−41 km.
It was a "giant" comet, much more active than a normal comet for its distance to the Sun, with an absolute magnitude of 1.5−3.5, it could have been up to a hundred times brighter than an average new comet. It had an unusually disrupted or "turbulent" appearance. It was also unusual in that the spectrum of its tail showed a strong predominance of the ion CO+, a result previously seen unambiguously only in Comet Morehouse (C/1908 R1).