A
- Adorn
- A river of Rohan, arising in the White Mountains. Together with the river Isen, it formed the western border of the Kingdom of Rohan. Adorn joined with the Isen about 150 miles (240 km) west of the Gap of Rohan.
- The triangle of land between the Isen, Adorn, and the White Mountains was nominally part of the Kingdom of Rohan, but in the late Third Age it was a contested area between the Rohirrim and the Dunlendings.
- Agathurush
- See Gwathló
- Anduin
- Angren
- See Isen
- Adurant
- The sixth and most southerly tributary of Gelion, the others being Ascar, Thalos, Legolin, Brilthor and Duilwen. It was the last of the seven rivers that defined Ossiriand.
- The name means double stream in Ilkorin, referring to a parting of the river about the isle of Tol Galen, and many more along its path due to its slow current.
- Aros
- The southern river of Doriath and northern tributary of Sirion. It rose in the northern lands around Himring and met Sirion in the south-west at Aelin-uial. It formed the southern border of the Kingdom of Doriath.
- Ascar
- A river in Ossiriand. The name means rushing, impetuous. It was the northern-most tributary of Gelion, and the second river of Ossiriand. After the Sack of Doriath by Dwarves, Beren Erchamion fought and killed the looters there. Doriath's treasure was lost in Ascar, and it was renamed Rathlóriel ('Goldenbed').
Read more about this topic: List Of Middle-earth Rivers