Yangshan Port (Chinese: 洋山港, p Yángshān Gǎng, Wu Yan-se Kaon), formally the Yangshan Deep-Water Port (洋山深水港, p Yángshān Shēnshuǐ Gǎng, Wu Yan-se Sen-sy Kaon), is a deep water port for container ships in Hangzhou Bay south of Shanghai. Connected to Shanghai's Pudong New Area by the Donghai Bridge and forming part of the Port of Shanghai, the islands of Greater and Lesser Yangshan are administered separately as part of Zhejiang's Shengsi County.
Built to allow the Port of Shanghai to grow despite shallow waters near the shore, it allows berths with depths of up to 15 metres (49 ft) to be built, and can handle today's largest container ships. The port is built on the islands of Greater and Lesser Yangshan, part of the Zhoushan archipelago, with fill from land reclamation.
It is connected to the mainland via the 32.5 km (20.2 mi) Donghai Bridge, opened on 1 December 2005 as the world's longest sea bridge. The six-lane highway bridge took 6,000 workers two and half years to construct.
In 2015, the port handled 36.54 million TEU up 3.5% over 2014.  In 2013 the volume was 33.6 million TEU. In mid-2011, port officials said the port was on track to move 12.3 million TEUs during the year, up from 10.1 million TEUs in 2010.
In 2000 and 2001, the decision was made to commence construction on the first of four phases. The first two phases have nine berths in total along a 3 km (1.9 mi) quayside. The first phase, which opened in 2004, can accommodate 2.2 million containers annually and includes 10 quay cranes. The second phase was opened in December 2006, and comprises 72 hectares (180 acres) with 15 quay cranes. The third phase, opened in stages, was completed in 2010 with seven berths. The fourth phase, expected to open in 2015, will add 4 million TEUs to the port's annual capacity.