Trenčín District Okres Trenčín
District
Country	Slovakia
Region (kraj)	Trenčín Region
Area
• Total	675 km2 (261 sq mi)
Population  (2024)
• Total	113,225
• Density	170/km2 (430/sq mi)
Time zone	UTC+01:00 (CET)
• Summer (DST)	UTC+02:00 (CEST)

Trenčín District (Slovak: okres Trenčín (or Trenčiansky okres), Hungarian: Trencséni járás) is a district in the Trenčín Region of northwestern Slovakia. It borders the districts of Bánovce nad Bebravou, Nové Mesto nad Váhom, and Ilava. In the northwest, the Slovak state border also forms the border of the Trenčín district.^[1]

Until 1918, the district was part of the county of Kingdom of Hungary of Trencsén.

The central part of the district, the Trenčianska kotlina basin and a part of the Ilavská kotlina basin are skirted by the White Carpathians to the west and the Strážov Mountains and the Považský Inovec in the east.^[1]

The most important industries are engineering and electrical engineering. In the past also the textile and clothing industries were of importance. In the Trenčianske Teplice spa locomotive and nervous system diseases are treated.^[1]

The district consists of 3 towns and 34 municipalities. The district seat is Trenčín, which is also the oldest (founded in 1111) and most populous town of the district with 55,698 inhabitants in 2015. The smallest municipality is Petrova Lehota with 183 inhabitants. The youngest municipality is Štvrtok, which was founded in 1477. The municipalities with the lowest elevation are Ivanovce and Štvrtok, at an elevation of 197 metres (646 ft) above sea level. The highest municipality is Dolná Poruba at 427 metres (1,401 ft) above sea level.^[1]

48°54′N 18°02′E / 48.900°N 18.033°E / 48.900; 18.033