A sailboat or sailing boat is a boat propelled partly or entirely by sails.

The term covers a variety of boats, larger than small vessels such as sailboards and smaller than sailing ships, but distinctions in size are not strictly defined and what constitutes a sailing ship, sailboat, or a smaller vessel (such as a sailboard) varies by region and culture.

Today, the most common sailboat is the sloop which features one mast and two sails, a normal mainsail and a foresail. This simple configuration is very efficient for sailing towards the wind.

In the sloop, the mainsail is attached to the mast and the boom, which is a spar capable of swinging across the boat, depending on the direction of the wind.

Depending on the size and design of the foresail it can be called a jib, genoa, or spinnaker.

It is possible but not common for a sloop to carry two foresails from the one forestay at one time (wing on wing). The forestay is a line or cable running from near the top of the mast to a point near the bow.

In Bermuda, where a rig design influenced by the Lateen rig appeared on boats and came to be known as the Bermuda rig, a large spinnaker was carried on a spinnaker boom when running down-wind.