:1948 U.S. National Championships (tennis)

{{Use mdy dates|date=July 2023}}

{{Use American English|date=July 2023}}

{{TennisEventInfo|1948|U.S. National Championships|

| date = September 10–19

| edition = 68th

| category = Grand Slam (ILTF)

| location = Forest Hills, New York City
Chestnut Hill, Massachusetts
United States

| venue=West Side Tennis Club
Longwood Cricket Club

| surface = Grass

| champms={{flagicon|USA}} Pancho Gonzales

| champws={{flagicon|USA}} Margaret Osborne duPont

| champmd={{flagicon|USA}} Gardnar Mulloy / {{flagicon|USA}} Bill Talbert

| champwd={{flagicon|USA}} Louise Brough / {{flagicon|USA}} Margaret Osborne

| champxd={{flagicon|USA}} Louise Brough / {{flagicon|USA}} Tom Brown

}}

The 1948 U.S. National Championships (now known as the US Open) was a tennis tournament that took place on the outdoor grass courts in the United States. The men's and women's singles events as well as the mixed doubles were held at the West Side Tennis Club, Forest Hills in New York City, while the men's and women's doubles events were played at the Longwood Cricket Club in Chestnut Hill, Massachusetts. The tournament ran from September 10 until September 19. It was the 68th staging of the U.S. National Championships, and the fourth Grand Slam tennis event of the year. Pancho Gonzales and Margaret Osborne duPont won the singles titles.{{cite book|title=Dunlop Lawn Tennis Almanack 1949|date=1949|publisher=Ed. J. Burrow & Co. Ltd.|location=London|pages=159–165|editor=G.P. Hughes|editor-link=Pat Hughes (tennis)}}{{cite book|last=Collins|first=Bud|title=The Bud Collins History of Tennis|year=2010|publisher=New Chapter Press|location=[New York]|isbn=978-0942257700|edition=2nd|pages=86–88}}