L'Obert dels Estats Units o US Open és un torneig Grand Slam de tennis creat l'any 1881. Actualment se celebra durant dues setmanes entre agost i setembre sobre superfície dura al complex USTA Billie Jean King National Tennis Center de Flushing Meadows, Nova York, Estats Units. Des de 1987 és el darrer Grand Slam del calendari.
Des de la seva creació ha canviat en diverses ocasions de seu: Newport (1881−1914), Forest Hills (1915−1920, 1924−1977) i Filadèlfia (1921−1923), fins que des del 1978 es disputa a l'emplaçament actual de Nova York. La primera edició estigué reservada a membres del club United States National Lawn Tennis Association (USNLTA) però en la següent ja es va obrir a tennistes internacionals. Actualment és l'únic Grand Slam en què es disputa un tie-break en el cinquè set, tot i que fins al moment no s'ha produït mai en una final. El tipus de superfície s'ha canviat en dues ocasions, inicialment es disputava sobre gespa (1881-1974), durant tres anys es va disputar sobre terra batuda Har-Tru (1975-1977) i el 1978 es va canviar a la superfície dura actual de DecoTurf.
La competició doble femenina se celebra des de l'any 1889, vuit anys després de la seva creació.
Palmarès U.S. National Championships Any Campiones Finalistes Resultat 1889 Margarette Ballard Bertha Townsend Marian Wright Laura Knight 6−0, 6−2 1890 Ellen Roosevelt Grace Roosevelt Margarette Ballard Bertha Townsend 6−1, 6−2 1891 20px|Irlanda Mabel Cahill Emma Leavitt Morgan Grace Roosevelt Ellen Roosevelt 2−6, 8−6, 6−4 1892 20px|Irlanda Mabel Cahill Adeline McKinlay Helen Day Harris Amy Williams 6−1, 6−3 1893 Aline Terry Harriet Butler Augusta Schultz M. Stone 6−4, 6−3 1894 Helen Hellwig Juliette Atkinson Annabella Wistar Amy Williams 6−4, 8−6, 6−2 1895 Helen Hellwig Juliette Atkinson (2) Elisabeth Moore Amy Williams 6−2, 6−2, 12−10 1896 Elisabeth Moore Juliette Atkinson Annabella Wistar Amy Williams 6−4, 7−5 1897 Juliette Atkinson Kathleen Atkinson Mrs. F. Edwards Elizabeth Rastall 6−2, 6−1, 6−1 1898 Juliette Atkinson Kathleen Atkinson (2) Marie Wimer Carrie Neely 6−1, 2−6, 6−4, 6−1 1899 Jane Craven Myrtle McAteer Maud Banks Elizabeth Rastall 6−1, 6−1, 7−5 1900 Edith Parker Hallie Champlin Marie Wimer Myrtle McAteer 9−7, 6−2, 6−2 1901 Juliette Atkinson Myrtle McAteer Marion Jones Elisabeth Moore Renúncia 1902 Juliette Atkinson Marion Jones Maud Banks Winona Closterman 6−2, 7−5 1903 Elisabeth Moore Carrie Neely Miriam Hall Marion Jones 8−4, 6−1, 6−1 1904 May Sutton Bundy Miriam Hall Elisabeth Moore Carrie Neely 3−6, 6−3, 6−3 1905 Helen Homans Carrie Neely Marjorie Oberteuffer Virginia Maule 6−0, 6−1 1906 Ann Burdette Coe Ethel Bliss Platt Helen Homans Clover Boldt 6−4, 6−4 1907 Marie Wimer Carrie Neely Edna Wildey Natalie Widley 6−1, 2−6, 6−4 1908 Evelyn Sears Margaret Curtis Carrie Neely Miriam Steever 6−3, 5−7, 9−7 1909 Hazel Hotchkiss Wightman Edith Rotch Dorothy Green Louise Moyes 6−1, 6−1 1910 Hazel Hotchkiss Wightman Edith Rotch (2) Adelaide Browning Edna Wildey 6−4, 6−4 1911 Hazel Hotchkiss Wightman Eleonora Sears Dorothy Green Florence Sutton 6−4, 4−6, 6−2 1912 Dorothy Green Mary K. Browne Maud Barger Wallach Mrs. Frederick Schmitz 6−2, 5−7, 6−0 1913 Mary K. Browne Louise Riddell Williams Dorothy Green Edna Wildey 12−10, 2−6, 6−3 1914 Mary K. Browne Louise Riddell Williams Louise Raymond Edna Wildey 10−8, 6−2 1915 Hazel Hotchkiss Wightman Eleonora Sears (2) Helen McLean Mrs. G. L. Chapman 10−8, 6−2 1916 Molla Bjurstedt Mallory Eleonora Sears Louise Raymond Edna Wildey 4−6, 6−2, 10−8 1917 Molla Bjurstedt Mallory Eleonora Sears (2) Phyllis Walsh Grace Moore LeRoy 6−2, 6−4 1918 Marion Zinderstein Eleanor E. Goss Molla Bjurstedt Mallory Mrs. Johan Rogge 7−5, 8−6 1919 Marion Zinderstein Eleanor E. Goss Eleonora Sears Hazel Hotchkiss Wightman 10−8, 9−7 1920 Marion Zinderstein Eleanor E. Goss (3) Eleanor Tennant Helen Baker 6−3, 6−1 1921 Mary K. Browne Louise Riddell Williams (3) Helen Gilleaudeau Aletta Bailey Morris 3−6, 6−4, 12−10 1922 Marion Zinderstein Jessup Helen Wills Moody Edith Sigourney Molla Bjurstedt Mallory 6−1, 4−6, 6−4 1923 Kitty McKane Godfree Phyllis Covell Hazel Hotchkiss Wightman Eleanor Goss 6−2, 6−2 1924 Hazel Hotchkiss Wightman Helen Wills Moody Eleanor Goss Marion Zinderstein Jessup 2−6, 6−3, 6−4 1925 Mary K. Browne Helen Wills Moody May Sutton Bundy Elizabeth Ryan 3−6, 6−3, 7−5 1926 Elizabeth Ryan Eleanor E. Goss Mary Kendall Browne Charlotte Chapin 3−6, 6−4, 12−10 1927 Kitty McKane Godfree Ermyntrude Harvey Betty Nuthall Joan Fry 6−1, 4−6, 6−4 1928 Hazel Hotchkiss Wightman Helen Wills Moody (2) Edith Cross Anna McCune Harper 6−2, 6−2 1929 Phoebe Holcroft Watson Peggy Mitchell Phyllis Covell Dorothy Shepherd 2−6, 6−3, 6−4 1930 Betty Nuthall Shoemaker Sarah Palfrey Cooke Edith Cross Anna McCune Harper 3−6, 6−3, 7−5 1931 Betty Nuthall Shoemaker Eileen Bennett Whittingstall Helen Hull Jacobs Dorothy Round Little 6−2, 6−4 1932 Helen Jacobs Sarah Palfrey Cooke Edith Cross Anna McCune Harper 3−6, 6−3, 7−5 1933 Betty Nuthall Shoemaker Freda James Helen Wills Moody Elizabeth Ryan Renúncia 1934 Helen Jacobs Sarah Palfrey Cooke Carolin Babcock Stark Dorothy Andrus 4−6, 6−3, 6−4 1935 Helen Jacobs Sarah Palfrey Cooke (3) Carolin Babcock Stark Dorothy Andrus 6−4, 6−2 1936 Marjorie Gladman Van Ryn Carolin Babcock Stark Helen Hull Jacobs Sarah Palfrey Cooke 9−7, 2−6, 6−4 1937 Sarah Palfrey Cooke Alice Marble Marjorie Gladman Van Ryn Carolin Babcock Stark 7−5, 6−4 1938 Sarah Palfrey Cooke Alice Marble Simonne Mathieu Jadwiga Jędrzejowska 6−8, 6−4, 6−3 1939 Sarah Palfrey Cooke Alice Marble Kay Stammers Freda James Hammersley 7−5, 8−6 1940 Sarah Palfrey Cooke Alice Marble (4) Dorothy Bundy Cheney Marjorie Gladman Van Ryn 6−4, 6−3 1941 Sarah Palfrey Cooke Margaret Osborne duPont Dorothy Bundy Cheney Pauline Betz 3−6, 6−1, 6−4 1942 Louise Brough Clapp Margaret Osborne duPont Pauline Betz Doris Hart 2−6, 7−5, 6−0 1943 Louise Brough Clapp Margaret Osborne duPont Patricia Canning Todd Mary Arnold Prentiss 6−1, 6−3 1944 Louise Brough Clapp Margaret Osborne duPont Pauline Betz Doris Hart 4−6, 6−4, 6−3 1945 Louise Brough Clapp Margaret Osborne duPont Pauline Betz Doris Hart 6−3, 6−3 1946 Louise Brough Clapp Margaret Osborne duPont Patricia Canning Todd Mary Arnold Prentiss 6−1, 6−3 1947 Louise Brough Clapp Margaret Osborne duPont Patricia Canning Todd Doris Hart 5−7, 6−3, 7−5 1948 Louise Brough Clapp Margaret Osborne duPont Patricia Canning Todd Doris Hart 6−4, 8−10, 6−1 1949 Louise Brough Clapp Margaret Osborne duPont Shirley Fry Irvin Doris Hart 6−4, 10−8 1950 Louise Brough Clapp Margaret Osborne duPont Shirley Fry Irvin Doris Hart 6−2, 6−3 1951 Shirley Fry Irvin Doris Hart Nancy Chaffee Patricia Canning Todd 6−4, 6−2 1952 Shirley Fry Irvin Doris Hart Louise Brough Clapp Maureen Connolly 10−8, 6−4 1953 Shirley Fry Irvin Doris Hart Louise Brough Clapp Margaret Osborne duPont 6−2, 7−9, 9−7 1954 Shirley Fry Irvin Doris Hart (4) Louise Brough Clapp Margaret Osborne duPont 6−4, 6−4 1955 Louise Brough Clapp Margaret Osborne duPont Shirley Fry Irvin Doris Hart 6−3, 1−6, 6−3 1956 Louise Brough Clapp Margaret Osborne duPont Shirley Fry Irvin Betty Pratt 6−3, 6−0 1957 Louise Brough Clapp Margaret Osborne duPont (12) Althea Gibson Darlene Hard 6−2, 7−5 1958 Jeanne Arth Darlene Hard Althea Gibson Maria Bueno 2−6, 6−3, 6−4 1959 Jeanne Arth Darlene Hard (2) Althea Gibson Sally Moore 6−2, 6−3 1960 Maria Bueno Darlene Hard Ann Haydon Jones Deidre Catt 6−1, 6−1 1961 Darlene Hard Lesley Turner Edda Buding Yola Ramírez Ochoa 6−4, 5−7, 6−0 1962 Maria Bueno Darlene Hard (2) Karen Hantze Billie Jean King 4−6, 6−3, 6−2 1963 Robyn Ebbern Margaret Court Maria Bueno Darlene Hard 4−6, 10−8, 6−3 1964 Billie Jean King Karen Hantze Susman Margaret Court Lesley Turner 3−6, 6−2, 6−4 1965 Carole Caldwell Graebner Nancy Richey Billie Jean King Karen Hantze Susman 6−4, 6−4 1966 Maria Bueno Nancy Richey Billie Jean King Rosemary Casals 6−3, 6−4 1967 Rosemary Casals Billie Jean King Mary-Ann Eisel Donna Floyd Fales 4−6, 6−3, 6−4
US Open