1999 in sumo
| Years in sumo | 
| 1999 in sports | 
|---|
| 
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In 1999, Musashimaru firmly established his position as the dominant sumo wrestler of the year. Born in American Samoa and raised in Hawaii, Musashimaru became only the second foreign-born wrestler in history to achieve the highest rank of yokozuna or grand champion, in May 1999. He finished the year having won four tournaments, a rare accomplishment.
The following are the events in professional sumo in Japan during 1999.