| Dysna | |
| Source1 Location: | Ignalina district municipality |
| Mouth: | Daugava |
| Mouth Coordinates: | 55.565°N 28.2283°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Lithuania, Belarus |
| Length: | 176km (109miles) |
| Discharge1 Avg: | 3.59m3/s |
| Basin Size: | 8193km2 |
| Tributaries Left: | Janka |
| Tributaries Right: | Birvėta, Avuta |
The Dysna (Belarusian: Дзісна|Dzisna; Russian: Дисна|Disna) is a river that flows through Lithuania and Belarus into the Daugava River near the town of Dzisna.
The river originates from Lake Parsvėtas, near Dūkštas, Ignalina district municipality. It flows through Lake Dysnai and Lake Dysnykštis. Near Kačergiškės it turns east and for 39 km flows along the Lithuanian-Belarusian border. The length of the Dysna in Lithuania is 17 km. One of the lakes in the basin area is Lake Drūkšiai that used to support the now decommissioned Ignalina Nuclear Power Plant.
The Dysna's largest tributaries are the Birvėta, Golbica, Janka, Berezovka, and Mnuta.