Sekolah Menengah Sains Johor (SMSJ) (Science Johore Secondary School), is a boarding school located in Kluang, Johor, Malaysia. Established in 23 May 1973, SMSJ is the first boarding school or Sekolah Berasrama Penuh (SBP) ever built in the state of Johor. SMSJ is the 16th SBP built in Malaysia under the 2nd Malaysia Plan. In 2011, the school celebrates its 38th year of operation. The school is widely known as Science Johore and a student of this school bears the name Science Johorean.