Laemostenus janthinus is a species in the beetle family Carabidae.
Laemostenus janthinus can reach a length of about . It is a nocturnal predator of other small arthropods.
This species can be found in Austria, Bosnia, Croatia, France, Italy, Poland, Slovenia and Switzerland.
This species inhabits forests and Alpine prairies at an elevation of 2000âÂÂ2400 meters above sea level.