Longkou is a county-level port city in northeastern Shandong province, China, administered by the prefecture-level city of Yantai. It was formerly known as Huang County. The city lies in the northwest of the Jiaodong Peninsula, on the south bank of Bohai Bay, with the Bohai Sea to its north and Laizhou Bay to its west.
Longkou covers a total area of 901 square kilometers and is bordered by Penglai District to the east and by Qixia City and Zhaoyuan City to the south. Across the sea to the north and west it faces the cities of Tianjin and Dalian. The city's jurisdiction is divided into 5 subdistricts, 8 towns and 1 high-tech industrial park.
Its position on the Bohai Sea coast makes the port a defining feature of the city, which sits on the south bank of Bohai Bay in the northwest of the Jiaodong Peninsula.