| 120P/Mueller | |
| Discoverer: | Jean Mueller |
| Discovery Date: | October 18, 1987 |
| Designations: | 1987 XXXI; 1995 O2 |
| Epoch: | 2022-01-21 |
| Semimajor: | 3.963 AU |
| Perihelion: | 2.478 AU |
| Aphelion: | 5.448 AU |
| Eccentricity: | 0.3746 |
| Period: | 7.88 yr |
| Inclination: | 8.4899° |
| Last P: | May 7, 2021 February 22, 2013[1] September 30, 2004 |
| Next P: | 2029-Apr-05 |
120P/Mueller, also known as Mueller 1, is a periodic comet in the Solar System. It last came to perihelion in May 2021 and underwent a 1.4 magnitude outburst in August 2021,[2] (after perihelion).