A shipyard, also called a dockyard or boatyard, is a place where ships are built and repaired. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Compared to shipyards, which are sometimes more involved with original construction, dockyards are sometimes more linked with maintenance and basing activities. The terms are routinely used interchangeably, in part because the evolution of dockyards and shipyards has often caused them to change or merge roles.

Countries with large shipbuilding industries include Australia, Brazil, Canada, China, Croatia, Denmark, Finland, France, Germany, India, Ireland, Italy, Japan, the Netherlands, Norway, the Philippines, Poland, Romania, Russia, Singapore, South Korea, Spain, Sweden, Taiwan, Turkey, the United Arab Emirates, Ukraine, the United Kingdom, the United States and Vietnam. The shipbuilding industry is more fragmented in Europe than in Asia where countries tend to have fewer, larger companies. Many naval vessels are built or maintained in shipyards owned or operated by the national government or navy.

Shipyards are constructed near the sea or tidal rivers to allow easy access for their ships. The United Kingdom, for example, has shipyards on many of its rivers.

The site of a large shipyard will contain many specialised cranes, dry docks, slipways, dust-free warehouses, painting facilities and extremely large areas for fabrication of the ships. After a ship's useful life is over, it makes its final voyage to a ship-breaking yard, often on a beach in South Asia. Historically ship-breaking was carried out in drydock in developed countries, but high wages and environmental regulations have resulted in movement of the industry to third-world regions.

The oldest structure sometimes identified as a dockyard was built c. 2400 BC by the Indus Valley civilisation in the Harappan port city of Lothal (in present-day Gujarat, India). Lothal engineers accorded high priority to the creation of a dockyard and a warehouse to serve the purposes of maritime trade. The name Naupactus, an ancient Greek city on the Gulf of Corinth, means "shipyard" (combination of the Greek words ναύς naus: "ship, boat"; and πήγνυμι pêgnumi, pegnymi: "builder, fixer"). Naupactus' reputation in this field extended back into legendary times – the site is traditionally identified by Greek authors such as Ephorus and Strabo as the place where a fleet was said to have been built by the legendary Heraclidae Other early historical shipyards include Tel Abu Saifi, in the Northern Sinai, a 4th-century BCE, Ptolemaic Era, Egyptian dockyard, with two dry docks. Narni was a shipyard of Ancient Rome.

In the Spanish city of Barcelona, the Drassanes shipyards were active from at least the mid-13th century until the 18th century, although at times they served as a barracks for troops as well as an arsenal. During their time of operation the Drassanes were continuously changed, rebuilt and modified, but two original towers and part of the original eight construction-naves remain today. From the 14th century, several hundred years before the Industrial Revolution, ships were the first items to be manufactured in a factory – in the Venice Arsenal of the Venetian Republic in present-day Italy. The Arsenal apparently mass-produced nearly one ship every day using pre-manufactured parts and assembly lines. At its height in the 16th century the enterprise employed 16,000 people. Spain built component ships of the Great Armada of 1588 at ports such as Algeciras or Málaga. In the 17th and 18th centuries, shipyards developed in complexity, with yards such as Blackwall Yard (1614 to 1987), the Scotts Shipbuilding and Engineering Company in Greenock, Scotland (1711–1984) and the Kraljevica Shipyard (1729 and still operating) being established. Havana was long the only dockyard in the Caribbean during the colonial period, the Santísima Trinidad, the largest warship of its time, was built there in 1769. Royal Naval Dockyards in the UK also expanded at this time, (including Woolwich, Deptford, Chatham, Portsmouth and Devonport), Gibraltar, Bombay, Bermuda, Hong Kong and elsewhere worldwide. Similarly, other countries in this period include the Nantes-Indret yard in France (established in 1771 it built ships for the American Revolution including the Deane), Charlestown Navy Yard, later Boston Navy Yard, Boston, Massachusetts (1800 to 1974), the Navy Island, Ontario, Canada (French in the 18th century, then British 1763 to War of 1812), the Philadelphia Naval Shipyard (1799 to 1995), at two locations, and the Portsmouth Naval Shipyard, located on Maine-New Hampshire border (1800 to present, making it the oldest continuously operating shipyard of the US Navy).

The Industrial revolution saw the creation of many new shipyards around the world. In the UK, these included Thames Ironworks and Shipbuilding Co. Ltd (1837 to 1912), William Denny and Brothers in Dumbarton, Scotland (1840 to 1963), John Brown & Company, Scotland (1851 to 1972), Swan Hunter (1880 to 2006), Harland & Wolff – (1861 - still a working yard) and Cammell Laird (1828, still a working yard). In Europe, other examples include Blohm+Voss (1877) where Bismarck was constructed (still a major yard). Ulstein Verft in Norway was established in 1917 (still a working yard under the Ulstein Group). In France, Chantiers de l'Atlantique (STX France) was established in 1861 (and is still a working yard). 3. Maj was one of the largest shipyard in the Mediterranean, established in 1892 in Rijeka (it is still a working yard). SLKB Komarno (Komárno) – Slovak Shipyard Komárno was another European shipyard on the Danube (established in 1898). Jean Street Shipyard (1843–present) is the oldest continually operated shipyard in the U.S. Located on the Hillsborough River in Tampa, Florida. Gloucester Marine Railways in the US (1859–present) is the oldest working shipyard in New England, being located on Rocky Neck in Gloucester, Massachusetts.

During the late industrial revolution, British shipyards were among the largest in the world, including Harland & Wolff in Belfast, John Brown & Company at Clydebank (Glasgow) and Swan Hunter at Wallsend (Tyne). By the 20th century, large shipyards were built during conflicts such as the First World War and Second World War. The Sun Shipbuilding & Drydock Co. in Chester, Pennsylvania was the largest shipyard in the world by 1945, employing some 40,000 workers and building hundreds of ships during the Second World War. Other examples of historical US yards include Mare Island Naval Shipyard, Mare Island, California (1854 to 1996), New York Naval Shipyard (NYNSY), also known as the Brooklyn Navy Yard, the New York Navy Yard, and United States Navy Yard, New York (1801 to 1966), San Francisco Naval Shipyard, later Hunters Point Naval Shipyard, then Treasure Island Naval Station Hunters Point Annex (1941 to 1994) and Long Beach Naval Shipyard (1943 to 1997).