Nord Stream (former names: North Transgas and North European Gas Pipeline; Russian: Северный поток, Severny potok) is an offshore natural gas pipeline from Vyborg in Russia to Greifswald in Germany. It is owned and operated by Nord Stream AG. The name occasionally has a wider meaning, including the feeding onshore pipeline in Russia, and further connections in Western Europe.

The project, which was promoted by the government of Russia and agreed to by the government of Germany, was seen as controversial for various reasons, including increasing European energy dependence on Russia and potential environmental damage.

The project includes two parallel lines. The first line of the pipeline was laid by May 2011 and was inaugurated on 8 November 2011. The second line is to be laid in 2011–2012, after which the line will be delivering gas at full throughput. At 1,222 km (759 mi) long, it is the longest sub-sea pipeline in the world, surpassing the Langeled pipeline.

The original pipeline project started in 1997 when Gazprom and the Finnish company Neste (in 1998 merged with Imatran Voima to form Fortum, and 2004 separated again) formed the joint company North Transgas Oy for construction and operation of a gas pipeline from Russia to Northern Germany across the Baltic Sea. North Transgas cooperated with the German gas company Ruhrgas (later E.ON). A route survey in the Exclusive Economic Zones of Finland, Sweden, Denmark and Germany, and a feasibility study of the pipeline was conducted in 1998. Several routes were considered including routes with onshore segments through Finland and Sweden.