Washington Valley is an unincorporated community in the Whippany River valley within Morris Township in Morris County, in the U.S. state of New Jersey.

Morris Township is a township in Morris County, in the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 22,974, an increase of 668 (+3.0%) from the 2010 census count of 22,306, which in turn reflected an increase of 510 (+2.3%) from the 21,796 counted in the 2000 census. The township was named for Lewis Morris, colonial governor of New Jersey.