Asteroids discovered on December 20
40 named asteroids.
| # | Asteroid | Discovered | Discoverer |
|---|---|---|---|
| 1 | (4649) Sumoto | 1936-12-20 | M. Laugier |
| 2 | (2085) Henan | 1965-12-20 | Purple Mountain Observatory |
| 3 | (2886) Tinkaping | 1965-12-20 | Purple Mountain Observatory |
| 4 | (2427) Kobzar | 1976-12-20 | N. S. Chernykh |
| 5 | (2700) Baikonur | 1976-12-20 | N. S. Chernykh |
| 6 | (16358) Plesetsk | 1976-12-20 | N. S. Chernykh |
| 7 | (2904) Millman | 1981-12-20 | E. Bowell |
| 8 | (3130) Hillary | 1981-12-20 | A. Mrkos |
| 9 | (3334) Somov | 1981-12-20 | A. Mrkos |
| 10 | (3353) Jarvis | 1981-12-20 | E. Bowell |
| 11 | (3550) Link | 1981-12-20 | A. Mrkos |
| 12 | (3611) Dabu | 1981-12-20 | Purple Mountain Observatory |
| 13 | (3704) Gaoshiqi | 1981-12-20 | Purple Mountain Observatory |
| 14 | (4574) Yoshinaka | 1986-12-20 | Niijima, T., Urata, T. |
| 15 | (4896) Tomoegozen | 1986-12-20 | Niijima, T., Urata, T. |
| 16 | (3774) Megumi | 1987-12-20 | T. Kojima |
| 17 | (6185) Mitsuma | 1987-12-20 | T. Kojima |
| 18 | (5353) Baillie | 1989-12-20 | Y. Oshima |
| 19 | (5823) Oryo | 1989-12-20 | T. Seki |
| 20 | (5912) Oyatoshiyuki | 1989-12-20 | Niijima, T., Urata, T. |
| 21 | (5291) Yuuko | 1990-12-20 | Matsuyama, M., Watanabe, K. |
| 22 | (5686) Chiyonoura | 1990-12-20 | Matsuyama, M., Watanabe, K. |
| 23 | (10353) Momotaro | 1992-12-20 | S. Otomo |
| 24 | (8733) Ohsugi | 1996-12-20 | T. Kobayashi |
| 25 | (8926) Abemasanao | 1996-12-20 | T. Kobayashi |
| 26 | (8927) Ryojiro | 1996-12-20 | T. Kobayashi |
| 27 | (9104) Matsuo | 1996-12-20 | T. Kobayashi |
| 28 | (29701) Peggyhaas | 1998-12-20 | CSS |
| 29 | (49442) Kubokoichi | 1998-12-20 | F. Uto |
| 30 | (26664) Jongwon | 2000-12-20 | LINEAR |
| 31 | (191582) Kikadolfi | 2003-12-20 | Tesi, L., Fagioli, G. |
| 32 | (333043) Courtneymario | 2004-12-20 | Mt. Lemmon Survey |
| 33 | (333106) Lujan | 2004-12-20 | Mt. Lemmon Survey |
| 34 | (333146) Austin | 2004-12-20 | Mt. Lemmon Survey |
| 35 | (256369) Vilain | 2006-12-20 | B. Christophe |
| 36 | (210434) Fungyuancheng | 2008-12-20 | Lin, H.-C., Ye, Q.-z. |
| 37 | (333744) Pau | 2009-12-20 | J. M. Bosch |
| 38 | (421774) Jeffreyrose | 2009-12-20 | Mt. Lemmon Survey |
| 39 | (472054) Tupaia | 2009-12-20 | Mt. Lemmon Survey |
| 40 | (479553) Garyzema | 2009-12-20 | Mt. Lemmon Survey |