:1946 U.S. National Championships (tennis)

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

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

{{TennisEventInfo|1946|U.S. National Championships|

| date = August 31 – September 8

| edition = 66th

| category = Grand Slam (ILTF)

| location = Forest Hills, Queens
New York City, New York

| venue=West Side Tennis Club

| surface = Grass / outdoor

| champms={{flagicon|USA|1912}} Jack Kramer

| champws={{flagicon|USA|1912}} Pauline Betz Addie

| champmd={{flagicon|USA|1912}} Gardnar Mulloy / {{flagicon|USA|1912}} Bill Talbert

| champwd={{flagicon|USA|1912}} Louise Brough / {{flagicon|USA|1912}} Margaret Osborne

| champxd={{flagicon|USA|1912}} Margaret Osborne / {{flagicon|USA|1912}} Bill Talbert

}}

The 1946 U.S. National Championships (now known as the US Open) was a tennis tournament that took place on the outdoor grass courts at the West Side Tennis Club, Forest Hills in New York City, New York. The tournament ran from August 31 until September 8. It was the 66th staging of the U.S. National Championships, and the fourth Grand Slam tennis event of the year.{{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=82–84}}