Tatsuko Ohsako (Japanese: 大迫たつ子, born 8 January 1952) is a Japanese professional golfer who played on the LPGA of Japan Tour (JLPGA) and the LPGA Tour.

Ohsako won 45 times on the LPGA of Japan Tour between 1975 and 1991. She was the leading money winner on the LPGA of Japan Tour three times (1977, 1980, 1987).

One of Ohsako's JLPGA wins was co-sanctioned with the LPGA Tour, the 1980 Mazda Japan Classic.^[1][2]

Ohsako finished fifth at the LPGA Tour's qualifying school tournament in January 1978^[3] and played sparingly on the LPGA Tour from 1978 to 1984.

• 1975 (2) Japan Ladies Professional East vs. West, Matsushima Ladies Open
• 1977 (4) All-Star, Toyotomi Ladies, Mizuno Golf Tournament, Saikai National Park Ladies Open
• 1978 (4) Hokkaido Women's Open, Saikai National Park Ladies Open, Hokuriku Queens Cup, All-Star
• 1979 (3) Hiroshima Women's Open, Hokkaido Women's Open, Junon Women's Open
• 1980 (3) Northeast Queens, Japan LPGA Championship, Mazda Japan Classic (co-sanctioned with LPGA Tour)
• 1981 (2) Japan Women's Open, Tokai Classic
• 1982 (2) Hiroshima Women's Open, Japan Ladies Professional East vs West
• 1983 (4) Tokushima Tsukinomiya Ladies Classic Open, Fujisankei Ladies Classic, Canon Queens Cup, Japan LPGA Championship
• 1984 (4) Tohato Ladies, Japan Women's Open, Recruit Torabayu Cup, JLPGA Lady Borden Cup
• 1985 (5) Dunlop Ladies Open, Mizuno Open, Recruit Torabayu Cup, Kosaido Asahi Golf Cup, Tsumura Itsuki Classic
• 1986 (3) Kumamoto Cyuoh Ladies, Recruit Torabayu Cup, JLPGA Lady Borden Cup
• 1987 (4) Tohato Ladies, Hiroshima UCC Ladies, Toto Motors Ladies, Karuizawa 72 Tokyu Ladies Open
• 1988 (4) Tohato Ladies, UCC Ladies, Toto Motors Ladies, Japan LPGA Championship
• 1991 (1) Japan LPGA Championship

Tournament in bold denotes major championships on LPGA of Japan Tour.

No.	Date	Tournament	Winning score	Margin of victory	Runner-up
1	9 Nov 1980	Mazda Japan Classic	−9 (72-68-73=213)	3 strokes	Pat Bradley

• Tatsuko Ohsako at the LPGA of Japan Tour official site