A modern sailing ship is any large wind-powered vessel. Traditionally a sailing ship (or simply ship) is a sailing vessel that carries three or more masts with square sails on each. Large sailing vessels that are not ship-rigged may be more precisely referred to by their sail rig, such as schooner, barque (also spelled "bark"), brig, barkentine, brigantine or sloop.

There are many different types of sailing ships, but they all have certain basic things in common. Every sailing ship has a hull, rigging and at least one mast to hold up the sails that use the wind to power the ship.

The crew who sail a ship are called sailors or hands. They take turns to take the watch, the active managers of the ship and her performance for a period. Watches are traditionally four hours long. Some sailing ships use traditional ship's bells to tell the time and regulate the watch system, with the bell being rung once for every half hour into the watch and rung eight times at watch end (a four-hour watch).

Ocean journeys by sailing ship can take many months, and a common hazard is becoming becalmed because of lack of wind, or being blown off course by severe storms or winds that do not allow progress in the desired direction. A severe storm could lead to shipwreck, and the loss of all hands.

Sailing ships are limited in their maximum size compared to ships with heat engines, so economies of scale are also limited. The heaviest sailing ships (limited to those vessels for which sails were the primary means of propulsion) never exceeded 14,000 tons displacement. Sailing ships are therefore also very limited in the supply capacity of their holds, so they have to plan long voyages carefully to include many stops to take on provisions and, in the days before water makers, fresh water

In 1902 the sailing vessel Preussen was the first to assist handling of sails by making use of steam power without auxiliary engines for propulsion. The steam power was used to drive the winches, hoists and pumps. A similar ship Kruzenshtern, a very large sailing vessel without mechanical assists, had a crew of 257 men, compared to the Preussen, which required only 48 mens

The brig Niagara was the flagship of Commander Oliver Hazard Perry in the War of 1812, and is famous as the origin of the phrases "We have met the enemy and they are ours," and "Don't give up the ship

In 2006, automated control had been taken to the point where sails could be operated by one person using a central control unit, DynaRig. The DynaRig technology was first developed in the 1960s in Germany by W. Prolls as a propulsion alternative for commercial ships to prepare for a possible future energy crisis. The technology is a high-tech version of the same type of sail used by the Preussen, the "square-rigger". The main difference is that the yards do not swing around a fixed mast but are rigidly attached to a rotating mast. DynaRig along with extensive computerization was used in the proof-of-concept Maltese Falcon to enable it to be sailed with no crew aloft.

As of 2013, with increasing restrictions on use of bunker fuel, attempts were underway to develop hybrid sailing ships using automated sail and alternative fuels.