plessur district (, ) is a former administrative district in the canton of graubünden, switzerland. it had an area of and has a population of 40,707 in 2015. the former district is named after the river plessur which crosses it. however, the region along the plessur –and therefore the whole valley–is called schanfigg. it was replaced with the plessur region on 1 january 2017 as part of a reorganization of the canton.