The 41-year-old is also the sports director for the 2020 Tokyo organising committee, Kyodo news reported.
"I'm retiring from top-level competition, but will now concentrate on contributing to the Japanese sporting world," Murofushi told the Kyodo news agency.
Murofushi also finished ninth at his first Olympics in Sydney in 2000 and fifth in Beijing in 2008.
(Reporting by Ian Rodricks in Bengaluru; Editing by Toby Chopra)
