Taruna Nusantara Senior High School (also called Tarnus or TN) is a boarding senior high school with a high-rated discipline that is located in Magelang Regency, Central Java, Indonesia. The school gains a reputation from its strong emphasis on national values in addition to exceptional academic and leadership achievements. The school and its teaching method have been referred to as "the inspiration for the setting up of other top schools in Indonesia."

Taruna Nusantara can be translated as "Patriot of The Archipelago." The word Taruna itself also generally refers to Indonesia's military cadet, which has no direct relation to and should not be confused with the school and its students.

The idea for the school was made by then-Indonesian Minister of Defence and Security, Gen. Leonardus Benjamin Moerdani in 1985. He envisioned a civilian school that could educate the country's best talents and produce graduates who could continue carrying forward the national mission set by the nation's founding fathers. It was then followed by the signing of MoU by Indonesian Armed Forces and Taman Siswa, which is among the first local and formal educational groups in Indonesia, to set up and support a foundation called Lembaga Perguruan Taman Taruna Nusantara (LPTTN). It is this foundation that eventually crystallised Gen. Moerdani's vision and subsequently oversaw the operational process of the school.

The school was unveiled by the then-Commander of Armed Forces, Gen. Try Sutrisno in 1990. The whole campus, consisting of the school compound, students' dormitories, and teachers' housing complex, occupied an 18.5 ha site, donated by the neighboring Indonesian Military Academy. During the first six years, the school admitted 245 male students every year. Starting from 1996, it became a co-ed school by accepting the first batch of 70 female students, and to accommodate this change, the school area was expanded to 23 hectares.

To be able to attract outstanding teenagers, the school, backed by the politically and financially strong Armed Forces, offered full scholarships to all students. Its teachers also enjoyed above-average salaries and facilities. However, after the severe Asian currency crisis in 1997 and the change in the national political landscape thereafter, the school faced financial difficulties and withdrew its scholarship scheme in 2002 or when accepting its thirteenth batch of students. To date, some needy students still receive the scholarship, which is sponsored by private corporations, state's departments, local and regional governments, or its alumni.

Although the school is sometimes referred to as having military-like discipline, it is not in any way similar to the military. The school curriculum is no different from the national education curriculum; all students receive the same education as others at senior high schools in Indonesia, with additional courses and activities being specifically added to develop nationalism and leadership among the students as emphasized by the founder's original goal.

Contrary to many public opinions, students who graduated from the school do not have any obligation to attend the military academy and may choose to continue their higher education freely.

The school screening process for applicants includes academic, physical, and psychological tests, health checks, and interviews.