Masao Kato (加藤 正夫, Katō Masao, March 15, 1947 – December 30, 2004), also known as Kato Kensei (加藤剱正 Katō Kensei), was a Japanese professional go player at Nihon Ki-in and former president of the International Go Federation. He won 46 titles, including the Oza (王座, King) eight times in a row. He also became the 2nd player to reach 1,200 career wins.
| Domestic | ||
|---|---|---|
| Title | Wins | Runners-up |
| Kisei (棋聖, Board Master) | Challenged 4 times to the defending champion (1978, 1988, 1991, 1993) | |
| Meijin (名人, Grand Master, hosted by Asahi Shinbun) | 2 (1986, 1987) | 2 (1981, 1988) |
| Honinbo (本因坊) | 4 (1977–1979, 2002) | 5 (1969, 1980, 1995, 1997, 2003) |
| Tengen (天元, Center) | 4 (1978–1981) | 2 (1982, 1991) |
| Oza | 11 (1979, 1980, 1982–1989, 1993) | 3 (1981, 1990, 1994) |
| Judan (10-dan) | 7 (1976–1979, 1983, 1987, 1997) | 4 (1980, 1984, 1988, 1998) |
| Gosei (碁聖, Master of Go) | 3 (1976, 1977, 1987) | 4 (1978, 1981, 1984, 1988) |
| Agon Cup (阿含杯) | 3 (1995, 1996, 2003) | 1 (1997) |
| Ryusei (竜星, dragon star) | 2 (1998, 2001) | |
| NHK Cup | 1 (1988) | 3 (1974, 1993, 1994) |
| NEC Cup | 3 (1990, 1991, 1996) | 3 (1992, 1999, 2000) |
| Continental | ||
| China-Japan Agon Cup | 1 (2003) | |