The Ala-Buga (Kyrgyz: Ала-Буга, also Алабуга) is a left tributary of the Naryn in Naryn Region of Kyrgyzstan. The river is known as Arpa in its upper reaches until its confluence with the Bychan. The Ala-Buga is formed on the north slopes of the Torugart Too range and the south slopes of the Jaman Too mountains.

It is 180 kilometres (110 mi) long, and has a drainage basin of 5,820 square kilometres (2,250 sq mi). It has an average elevation of 3,290 metres (10,790 ft), an annual average flow rate of 31 cubic metres per second (1,100 cu ft/s), and an average specific discharge of 8.35 L/s•km.

Settlements located along the banks of Ala-Buga include Kosh-Döbö, Jerge-Tal and Kongorchok.