| Valdar Jaanusson | |
| Birth Date: | 1923 |
| Birth Place: | Nömme, Tallinn |
| Death Date: | August 28, 1999 |
| Death Place: | Täby, Stockholm |
| Citizenship: | Sweden |
| Nationality: | Swedish |
| Fields: | Stratigraphy |
| Workplaces: | Uppsala University Geological Survey of Finland Swedish Museum of Natural History |
| Alma Mater: | Uppsala University |
| Known For: | Confacies Jaanusson effect Ordovician geology Topostratigraphy |
Valdar Jaanusson (1923 – August 28, 1999) was an Estonian-Swedish geologist.[1] In 1960, he introduced the concept of topostratigraphy into Swedish stratigraphy.[2] A recognized expert on the geology of the Ordovician period, he was member of the Estonian Academy of Sciences.[3]