the 1933 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, united states. the tournament ran from 2 september through 10 september for the men's tournament and 14 august through 19 august for the women's tournament. it was the 53rd staging of the u.s. national championships and the fourth grand slam tennis event of the year.