Košarkaški klub Radnik (Serbian Cyrillic: Кошаркашки клуб Радник, transl. Radnik Basketball Club), currently known as Radnik Elvaco MetPro due to sponsorship reasons, is a men's professional basketball club based in Bijeljina, Republika Srpska, Bosnia and Herzegovina. They are currently competing in the First League of R Srpska.
The club is formed on 20 May 1961 as OKK Bijeljina and renamed as KK Radnik later.