| Minorplanet: | yes |
| 257 Silesia | |
| Background: |
|
| Discovery Ref: |   |
| Discovered: | 5 April 1886 |
| Mpc Name: | (257) Silesia |
| Pronounced: | [1] |
| Alt Names: | A886 GB, 1929 DD , 1952 HU |
| Named After: | Silesia   |
| Orbit Ref: |   |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Uncertainty: | 0 |
| Observation Arc: | 129.94 yr (47462 d) |
| Aphelion: | 3.4669abbr=onNaNabbr=on |
| Perihelion: | 2.7711AU |
| Semimajor: | 3.119AU |
| Eccentricity: | 0.11154 |
| Period: | 5.51 yr (2012.0 d) |
| Inclination: | 3.6351° |
| Asc Node: | 34.364° |
| Arg Peri: | 27.605° |
| Moid: | 1.78299AU |
| Rotation: | 15.7095abbr=onNaNabbr=on |
| Spectral Type: | B–V = 0.761 U–B = 0.384 SCTU Ch |
| Abs Magnitude: | 9.47 |
| Mean Motion: | / day |
| Jupiter Moid: | 1.8503AU |
| Tisserand: | 3.204 |
257 Silesia is a large Main belt asteroid, about 73 kilometers in diameter. It was discovered by Johann Palisa on 5 April 1886 at Vienna Observatory, Austria.
It is named after Silesia, the province of the discoverer's birthplace (nowadays most of Silesia is in Poland, but Palisa's birthplace is in the small part of Silesia that is in the Czech Republic).