Hikaru Hayashi (林 光 Hayashi Hikaru?, October 22, 1931 – January 5, 2012) was a contemporary Japanese composer, pianist and conductor.[1] Born in Tokyo, he was the cousin of flautist Ririko Hayashi.

Hayashi entered Tokyo University of the Arts as a composition student but did not complete his studies.[1] Studying under Hisatada Otaka, he produced many compositions including orchestral works. In particular, he was noted for his choral suite Scenes from Hiroshima (1958–2001).

In exploring the possibilities of Japanese language opera, Hayashi composed more than 30 operas. He was artistic director and resident composer of the Opera Theatre Konnyakuza. His oeuvre also includes symphonic works, works for band, chamber music, choral works, songs and more than 100 film scores. He was a frequent collaborator with film director Kaneto Shindo. Hayashi is the author of more than 20 books including Nihon opera no yume (日本オペラの夢 The Dream of Japanese Opera).[2]

In 1998 Hayashi won the 30th Suntory Music Award.

In September 2011, Hayashi collapsed in front of his home hitting his head. He was rushed to the hospital unresponsive.