The Netherlands was a country on Earth located on the continent of Europe. The people of the Netherlands were known as the Dutch. The Netherlands flag was three horizontal bands of red, white, and blue. (ENT: "First Flight") Its neighbor countries at times have been Germany, Belgium, France and across the channel Great Britain.
Amsterdam was a Dutch city, and one time in its history the capital city. The Amsterdam News, a black newspaper, was named after this city – its home city of New York having been founded by the Dutch and originally named New Amsterdam. (DS9: "Far Beyond the Stars")
Important people from the Netherlands were 17th century philosopher Benedict de Spinoza who wrote The Ethics, (TOS: "Where No Man Has Gone Before") and 19th century painter Vincent van Gogh, (TNG: "The Most Toys"; DS9: "Second Sight") and painter Johannes Vermeer who made paintings like The Concert. (VOY: "The Killing Game")
In the late 20th century, the Netherlands was a founding member of the European Space Agency. (ENT: "First Flight")
A large area of the Netherlands was flooded in April 2063. (Star Trek: First Contact)
In the alternate timeline created by Vosk and the Na'kuhl, Vladimir Lenin had been assassinated in 1916 and Russia had never become communist. Adolf Hitler therefore "quickly took England", being able to keep his focus on the West after the successful occupation of France, Belgium and the Netherlands. (ENT: "Storm Front, Part II")