Sai Kung District is the second largest district in Hong Kong in terms of area. It comprises the southern half of Sai Kung Peninsula and Clear Water Bay Peninsula in the New Territories plus a strip to the east of Kowloon. The administrative centre is Sai Kung Town but the district's population is concentrated in Tseung Kwan O New Town. The district has the second youngest residents. It consists of rural areas, new town and over 70 islands of various sizes. The unique characteristic of the district is that the traditional customs of rural villages.

Sai Kung District covers approximately 136 km² and as of 2006, it had a population of 406,442 in 2006, most of it in Tseung Kwan O.

In contrast to the densely populated areas of Hong Kong Island and Kowloon, Sai Kung District's heartland is a coastal area characterised by beautiful scenery, charming small villages and stunning seascapes. The area is known for its pristine beaches and quiet living. Inasmuch as it remains only partly urbanized, many people describe Sai Kung as the "last back garden" of Hong Kong.

Sai Kung Town (traditional Chinese: 西貢市; simplified Chinese: 西贡市; pinyin: Xīgòng Shì) or simply Sai Kung (traditional Chinese: 西貢; simplified Chinese: 西贡; pinyin: Xīgòng) is a town on Sai Kung Peninsula, facing the Sai Kung Hoi (Inner Port Shelter), part of Sai Kung District in the New Territories, Hong Kong. Sai Kung is the centre of the surrounding villages, and hence the name may refer to the areas in its immediate surroundings.

Having evolved from a fishing village, it is a paradise for seafood lovers, locals and foreign tourists alike. Visitors can stroll along the waterfront of Sai Kung Town or explore the lanes of the old town, visit the Tin Hau Temple, feast on seafood or enjoy different delicacies at Western-style pubs and restaurants.

Sai Kung Hoi was a fishing harbour and fishermen still gather there. The harbour is now a typhoon shelter, where motorized junks used in the local tourist trade now are moored. They are boats that now can be hired for fishing and swimming trips.

The development of the town has been remarkably restrained. There are few condominiums that rise above ten storeys. Before the relocation of the airport of Hong Kong from Kai Tak to Chep Lap Kok, the town was a popular residential area for airport staff from all over the world. The town, with its relatively clean air and slow pace of life, for Hong Kong, is still a popular place for many people of Hong Kong to live.