Krasnoborsky District (Russian: Краснобо́рский райо́н) is an administrative district (raion), one of the twenty-one in Arkhangelsk Oblast, Russia. Municipally, it is incorporated as Krasnoborsky Municipal District. It is located in the southeast of the oblast and borders with Verkhnetoyemsky District in the north, Udorsky District of the Komi Republic in the northeast, Lensky District in the east, Kotlassky District in the south, and with Ustyansky District in the west. Its administrative center is the rural locality (a selo) of Krasnoborsk. District's population: 13,815 (2010 census); 17,144 (2002 census); 20,491 (1989 Soviet census). The population of Krasnoborsk accounts for 34.5% of the district's total population.

The area was populated by speakers of Uralic languages and then colonized by the Novgorod Republic. After the fall of Novgorod, the area became a part of the Grand Duchy of Moscow. Krasnoborsk was founded in 1602 as Krasny Bor. From the 17th century, Krasny Bor held an annual trade fair.

In the course of the administrative reform carried out in 1708 by Peter the Great, the area was included into Archangelgorod Governorate. In 1780, the governorate was abolished and transformed into Vologda Viceroyalty. Simultaneously, Krasny Bor was renamed Krasnoborsk, granted town status, and Krasnoborsky Uyezd was established. In 1796, the uyezd was abolished, and its territory was included into Solvychegodsky Uyezd of Vologda Governorate. In 1918, the area was transferred to the newly established Northern Dvina Governorate and in 1924 the uyezds were abolished in favor of the new divisions, the districts (raions). Krasnoborsky District was established on April 10, 1924.

In the following years, the district remained within the same borders, but the first-level administrative division of Russia kept changing. In 1929, Northern Dvina Governorate was merged into Northern Krai, which in 1936 was transformed into Northern Oblast. In 1937, Northern Oblast was split into Arkhangelsk Oblast and Vologda Oblast. Krasnoborsky District remained in Arkhangelsk Oblast ever since.

From 1924 to 1959, Cherevkovsky District existed, with its administrative center located in Cherevkovo, initially in Northern Dvina Governorate. On September 11, 1959, the district was abolished and split between Krasnoborsky, Verkhnetoyemsky, and Ustyansky Districts; the administrative center Cherevkovo became a part of Krasnoborsky District.

The district is located on both banks of the Northern Dvina. A major part of the district belongs to the basins of the Northern Dvina and its major tributaries. The main (right-hand) Northern Dvina tributary which flows through the district is the Uftyuga. Minor parts of the district belong to the basins of other major tributaries of the Northern Dvina: the Ustya (southwest) and the Pinega (northeast). The source of the Pinega is located in Verkhnetoyemsky District; however, the Pinega starts at the confluence of the Belaya and the Chyornaya, both of which have their sources in Krasnoborsky District. A very small area in the northeast of the district, adjacent to the Komi Republic, belongs to the basin of the Vashka River, a tributary of the Mezen (not of the Northern Dvina basin). The whole area of the district lies in the drainage basin of the White Sea.

Almost the whole of the district is covered by coniferous forests (taiga). The exception are the meadows in the floodplains.

Administratively, the district is divided into ten selsoviets. The following selsoviets have been established (the administrative centers are given in parentheses):