Osamu Miyazaki (born 23 January 1966) is a Japanese former professional Grand Prix motorcycle road racer. He was the first full-time rider in the championship from Japan. After winning his first race in the All Japan Road Race Championship at age 26, Miyazaki joined Aprilia and moved to Italy in 1996 to compete in the Grand Prix. After riding with Aprilla for three seasons, he raced with Yamaha, and helped them with the development of the TZ 250 and YZF-R6. In 2002, he won the Japanese Grand Prix. During his time with Aprilla and Yamaha, he had ridden with different teams, including Edo Racing and Motorex Daytona Yamaha. He left the Grand Prix circuit in 2004 to race in the All Japan Road Race Championship. He started his own team and 2008 and retired after the 2011 season.
Osamu Miyazaki was born on 23 January 1966 in Yamaguchi, Japan. He started racing when he was 23, when he entered the All Japan Road Race Championship riding 250 cc motorcycles, and won his first race in the championship three seasons later. At that time, he migrated to the Grand Prix, initially competing in the 1991 Japanese race. He subsequently entered the race the following year, coming thirteenth overall. Following this success, he joined the Italian Aprilia team, which at the time was not well known in Japan. He achieved his first points in 1995. He moved to Italy to race in the Grand Prix professionally, the second Japanese rider at the Championships and the first Japanese contender to participate full-time. In 1996, he was the last official "supply team" works bike rider and the only Japanese rider with Aprilla in the class. He raced as a member of the Japanese Edo Racing team but continued to race Aprilla bikes.
For the 1997 Grand Prix season, Miyazaki raced production Yamaha bikes. He remained with the Japanese Edo Racing team but received support from Yamaha in kit parts. Entering as a Japanese wildcard, he achieved his first win at the 2002 Japanese motorcycle Grand Prix at Suzuka while racing with Motorex Daytona Yamaha. He started at eighth place and finishing almost ten seconds ahead of the next competitor. He also achieved the record for the fastest circuit, with a time of two minutes 23.895 seconds and a top speed of , a record that stood for a year. The season was his last with the Grand Prix.
In 2004, Miyazaki moved to racing 600 cc motorcycles in the All Japan Road Race Championships. After four years, he had achieved second place at the end of the season. He started his own team in 2008 and took pole position the following year in the third round at Autopolis, but suffered a serious injury at the end of the season. He subsequently raced in 2010 and 2011, retiring shortly afterwards.
Miyazaki was involved in the development of the Yamaha TZ 250 and Yamaha YZF-R6. He worked with Dunlop Tyres in tyre R&D in 2004 and coached Chinese competitors in 2009.
() (Races in bold indicate pole position)