No one knows who invented the first sailboat. However, probably the first one was around 6,000 years ago on or around the year 4,000 BC!
The first documented proofs of a sailing boat are found in ancient Egypt, with papyrus and stones hinting at what was the first model of it.
Made of wood and papyrus itself, was mostly used to navigate the Nile river, some were made to fish while others to travel, carry goods or fight a war.
However, Austronesians were the first humans beings, about 5,000 years ago, to create sailing boats capable to navigate the oceans. It was therefore the Indo-Pacific world that independently added new technologies for round the world trips, such as the catamaran or the outrigger ship.