Grand Forks County is a county in the U.S. state of North Dakota. As of the 2020 census, its population was 73,170, making it the third most populous county in North Dakota. Its county seat and largest community is Grand Forks.

Grand Forks is the 3rd most populous city in the U.S. state of North Dakota and the county seat of Grand Forks County. According to the 2020 census, the city's population was 59,166. Grand Forks, along with its twin city of East Grand Forks, Minnesota, forms the center of the Grand Forks, ND-MN Metropolitan Statistical Area, which is often called Greater Grand Forks or the Grand Cities.