Viiksinselkä

Viiksinselkä () is a medium-sized lake in the Vuoksi main catchment area. It is located partly in the municipality of Ilomantsi in Finland and partly in Loimola municipality in Russia.

Viiksinselkä has an area of , of which belongs to Finland and to Russia. Its surface elevation is above sea level. The biggest island is Ostronsaari on the Finnish side, on which a village by the same name is located. The villages of Mutalahti and Nehvonniemi are also located by the lake.