Lüshunkou District is a district of Dalian, Liaoning province, China. Also formerly called Lüshun City or literally Lüshun Port, it was formerly known as both Port Arthur and Ryojun. The district's area is 512.15 km2 (197.74 sq mi) and its permanent population as of 2010 is 324,773.

Dalian is a major sub-provincial port city in Liaoning province, People's Republic of China, and is Liaoning's second largest city and the third-most populous city of Northeast China. Located on the southern tip of the Liaodong peninsula, it is the southernmost city in both Liaoning and the entire Northeast. Dalian borders the prefectural cities of Yingkou and Anshan to the north and Dandong to the northeast, and also shares maritime boundaries with Qinhuangdao and Huludao across the Liaodong Bay to west and northwest, Yantai and Weihai on the Shandong peninsula across the Bohai Strait to the south, and North Korea across the Korea Bay to the east.