| Rudolf Hoernes | |
| Birth Date: | 7 October 1850 |
| Birth Place: | Vienna |
| Death Place: | Judendorf-Straßengel (Styria) |
| Nationality: | Austrian |
| Fields: | Geology |
Rudolf Hoernes (7 October 1850 - 20 August 1912) was an Austrian geologist, born in Vienna, son of Moritz Hoernes. He studied under Eduard Suess and became a Professor of geology in Graz. He was known for his earthquake studies in 1878 and proposed a classification of earthquakes into subsidence earthquakes, volcanic earthquakes and tectonic earthquakes. In 1893, he published a detailed textbook on earthquake theory (Erdbebenkunde) from a geological point of view.