Tennen Rishin-ryū (天然理心流?) is a Japanese martial art, commonly known as the style practiced by several core members of the Shinsengumi.

Founded by Kondō Kuranosuke Nagahiro around 1789, the style was popularized by Kondō Shūsuke (1792-1867), the third generation master of the style, who, together with Satō Hikogorō, spread its practice throughout the farming population of the Tama district. Since the first and the second generation masters each adopted a student with superb skills to be the next master, in 1849 the childless Kondō Shūsuke decided to adopt a sixteen-year-old student named Miyagawa Katsugorō, the later Kondō Isami.

This style, like other koryū arts, teaches kenjutsu, bōjutsu, and jūjutsu. The style was famous in Edo, and was headquartered at the Shieikan dojo. In 1861, Kondō Isami became the 4th sōke of the style, spread its fame during his time as commander of the Shinsengumi. Noted practitioners were Hijikata Toshizo, Inoue Genzaburō, and the famous prodigy Okita Sōji (who mastered all the techniques of the school and attained Menkyo Kaiden status at eighteen or so.) Several men already certified in other styles cross-trained in Tennen Rishin-ryū, such as Yamanami Keisuke, who was enrolled in 1860 and others like Nagakura Shinpachi and Harada Sanosuke stayed at the Shieikan without becoming practitioners of Tennen Rishin-ryū.

Even though quite a few techniques were lost, especially in the beginning of the Meiji era, Tennen Rishin-ryū is still practiced today, among other koryū