The Alymdya (Russian: Алымдя o Алымджа; Yakut: Алымдьа), is a river in Yakutia (Sakha Republic), Russia.

The river heads roughly southeastwards and then southwards, crossing a cluster of small lakes and swamps.

Then it turns southeastwards again and keeps roughly that direction until its mouth at the confluence with the 191 km (119 mi) long Olguydakh from the left to form the Akhtaranda, 75 km (47 mi) from its mouth in the Vilyuy Reservoir.

[4][5] The main tributaries of the Alymdya are the 50 kilometres (31 mi) long Kurakkalyr (Кураккалыыр) from the right and the 66 kilometres (41 mi) long Alymdya-Tuorata (Алымдьа-Туората) from the left.

The river freezes in mid October and stays under ice until the second half of May.