Okita Sōji (沖田 総司, 1842 or 1844 – July 19, 1868) was a Japanese samurai and the captain of the first unit of the Shinsengumi, a special police force in Kyoto during the late shogunate period.

By that time, Kondo Shusuke had already adopted Shimazaki Katsuta (the later Kondō Isami), but Hijikata Toshizō had not yet enrolled at the Tennen Rishin-ryū school.

Okita proved to be a prodigy; he mastered all the techniques and attained the Menkyo Kaiden scroll (license of total transmission) in the ryū at the age of eighteen or so.

His brother-in-law Okita Rintarō, also a practitioner of the Tennen Rishin-ryū, became a commander of the Shinchōgumi (the Shinsengumi's brother league in Edo.

[7] Mediocre with the shinai, a master of the bokken/bokutou and bo staff, a fascinating trendsetter of the katana, his signature technique was named the Hyakkidou-ri[8] (which roughly translates as "no light blade" or "unenlightened blade") or Sandanzuki (which translates as "Three Piece Thrust"), a technique that could attack one's neck, left shoulder, and right shoulder with one strike.

It is a popular conception by the public that his tuberculosis was first discovered when he fainted during the Ikedaya incident, mostly due to the depiction appearing in a famous work chronicling the Shinsengumi as well as a number of period dramas based upon it.

While many of Shinsengumi fans believe that Yoshida Toshimaro was killed by Okita during the Ikedaya Affair (based on Shimosawa Kan and Shiba Ryōtarō's fiction), it is a historical inaccuracy.

[citation needed] In 1865, Okita became the captain of the first unit of the Shinsengumi and also served as a kenjutsu instructor;[12][13] later that year, he was appointed by Kondo Isami to be the fifth master of the Tennen Rishin-ryu after him.

Later that night, he was buried at Senshō-ji Temple in Azabu, Edo, under his birth name (with Okita Sōji listed in the death records).

Like the other members of the Shinsengumi, fictionalized accounts of Okita's life and actions appear in novels, period dramas and anime/manga series.