Lycée Josy Barthel (), abbreviated to LJBM, is a high school in Mamer, in south-western Luxembourg. It was opened in September 2003, and cost €67.4m to build. It is named after Josy Barthel, winner of Luxembourg's only Olympic gold medal-winner and former cabinet member.
The first denomination of the highschool was Lycée technique Josy Barthel and has been changed into Lycée Josy Barthel on 1st September 2009. Since then the school offers all class from 7th to 1st degree (enseignement secondaire).