Tomaszów County (Polish: powiat tomaszowski) is a unit of territorial administration and local government (powiat) in Lublin Voivodeship, eastern Poland, on the border with Ukraine.

It was established on January 1, 1999, as a result of the Polish local government reforms passed in 1998.

Its administrative seat and largest town is Tomaszów Lubelski, which lies 107 kilometres (66 mi) south-east of the regional capital Lublin.

The only other towns in the county are Tyszowce, lying 28 km (17 mi) north-east of Tomaszów, and Łaszczów, lying 25 km (16 mi) east of Tomaszów.

The county covers an area of 1,487.1 square kilometres (574.2 sq mi).