Abrene county (Latvian: Abrenes apriņķis) was a county in the Republic of Latvia with an area of 4,292 square kilometers (1,657 sq mi) that was formed in 1925 from the northern part of the Ludza county as Jaunlatgale county (New Latgale county, Jaunlatgales apriņķis), but was renamed Abrenes apriņķis in 1938.

The district included the towns of Balvi and Abrene and 14 villages, and the civil parishes (Latvian: pagasti) of the district were reorganized thrice (there were 12 in 1929, 13 in 1935 and 15 in 1940).

During World War II, six eastern civil parishes – Purvmalas (Bakovo), Linavas (Linovo), Kacēnu (Kachanovo), Upmalas (Upmala), Gauru (Gavry) and Augšpils (Vyshgorodok), as well as the town of Abrene (a total area of 1293.6 square kilometers with 35,524 inhabitants) – were annexed to the Russian Soviet Federative Socialist Republic in 1944. That part of the former Abrene district is now part of Russia as the Pytalovsky district of Pskov Oblast and borders Latvia. "Abrene region" in current usage often treats the area joined to Russia as though it had comprised the entire district, which can be misleading since nearly three quarters of the former district are in Latvia, but multiple treatments of the transfer of the eastern pagasti by citing interbellum demographic statistics for the whole region, rather than by civil parish.

The Abrene region was long a point of contact and friction between the Finno-Ugric, Baltic, and Slavic languages, cultures, tribes, and countries. The Russian name for the town and region, Pytalovo, probably derives from the Finno-Ugric tulva, "tributary, flood"; the region was part of Tolowa (or Tholowa; Latvian: Tālava), a kingdom of the northern Latgalians, which for a period paid tribute to Mstislav the Brave of Smolensk (from ca. 1180); the area became part of Livonia in 1224.

In the 1270s the area became a part of Livonia. The Balts east of a slight ridge at Viļaka were gradually russified from the 15–16th centuries, but the philologists August Johann Gottfried Bielenstein and Kārlis Mīlenbahs, conducting linguistic field research in the area in the late 19th and early 20th century, found that multiple people, called "Russian Latvians" by the local Russians, still spoke the High Latvian dialect.^{[citation needed]}

After the Bolsheviks were driven from what is now Latvia and Soviet Russia recognized Latvia's independence, in August 1920, the border was not drawn alongside ethnographic lines: once the frontier was negotiated (the border was not finalized until 7 April 1923) large Russian and Belarusian communities were left on the Latvian side. Strategic concerns also played a part, because of an important railway junction within the Abrene region. The historian Edgars Andersons explains (in Latvijas vēsture 1914–1920 [Stockholm: Daugava, 1976]):

"Especially in the north, the Russians had agreed to the Latvians' strategic demands, not complaining about the ethnographic principle having been disregarded. Several civil parishes were completely Russian."

The population of the entire district in the census of 1935, divided by ethnicity, was as follows: 60,145 Latvians, 45,885 Russians, 1,558 Jews and 648 Belarusians. The demographics differed sharply on either side of the Viļaka ridge, which bisects the district – the eastern civil parishes had small ethnic Latvian minorities: 17% in Kacēnu pagasts, 5% in Linavas pagasts, 32% in Purvmalas pagasts, 5% in Augšpils pagasts, and 4% in Gauru pagasts. The civil parishes immediately to the west had strong Latvian majorities, ranging from 71% in Šķilbēnu pagasts to 91% in Viļakas pagasts. The town of Abrene itself, which developed around the Pytalovo railroad station, had 1,242 inhabitants, 484 of them ethnic Latvians.