National High School of Mathematics and Natural Sciences "Academician Lyubomir Chakalov" (in Bulgarian: Национална природо-математическа гимназия "Академик Любомир Чакалов") is a high school (European secondary school) in Sofia, Bulgaria. It is located in Lozenets municipality. The school is named after the Bulgarian mathematician Lyubomir Chakalov. More than 1000 students are studying in the school. They are divided into six majors: