The Royal Netherlands Navy (Dutch: Koninklijke Marine, pronounced [ˈkoːnɪŋkləkə maːˈrinə], meaning 'Royal Navy') is the maritime service branch of the Netherlands Armed Forces. It traces its history to 8 January 1488, making it the third-oldest navy in the world.

During the 17th and early 18th centuries, the Dutch States Navy was one of the most powerful navies in the world and played an active role in the Anglo-Dutch Wars, Franco-Dutch War, Nine Years' War and War of the Spanish Succession. However, by the late 18th century it had declined through neglect and was no longer a match for either the British or French navies. The Batavian Navy and navy of the Kingdom of Holland played an active role in the French Revolutionary and Napoleonic Wars, though both were repeatedly yoked to French interests.

Officially formed in 1813 after the Sovereign Principality of the United Netherlands was established, the Royal Netherlands Navy played an important role in protecting the Dutch East Indies, and would play a minor role in World War II, where it fought against the Imperial Japanese Navy. Since World War II, the Royal Netherlands Navy has taken part in several peacekeeping missions, and frequently participates in European Union and NATO operations and exercises.

The international prefix for ships of the Royal Netherlands Navy is HNLMS (His/Her Netherlands Majesty's Ship). The Netherlands navy itself uses the prefixes Zr.Ms. (Dutch: Zijner Majesteits, lit. 'His Majesty's') when a King is on the throne, and Hr.Ms. (Dutch: Harer Majesteits, lit. 'Her Majesty's') when there is a Queen. Changes happen automatically at the end of a monarch's reign.

The modern Netherlands Navy dates its founding to a "statute of admiralty" issued by Maximilian, King of the Romans (future Holy Roman Emperor Maximilian I), and his son Philip the Fair, the ruler of Burgundian lands (a minor at that time) on 8 January 1488.

The Netherlands navy was involved in several wars against other European powers from the late 16th century, initially for independence against Spain in European waters, later for shipping lanes, trade and colonies in many parts of the world, notably during the Anglo-Dutch Wars. During the 17th century the Dutch States Navy was one of the most powerful navies in the world. As an organization, the Dutch navy consisted of five separate admiralties (three of them in Holland, and one each in Friesland and Zeeland), each with its own ships, personnel, shipyards, command structures and revenues.

At the start of WW2 the Dutch had five cruisers, eight destroyers, 24 submarines, and smaller vessels, along with 50 aircraft. The Netherlands was conquered in 1940 by Nazi Germany in a matter of days, and two Dutch light cruisers and one destroyer leader and three destroyers that were under construction were captured in their shipyard.

For the rest of the war, the Dutch navy was based in Allied countries: the Dutch navy had its headquarters in London, and smaller units in Ceylon (modern day Sri Lanka) and Western Australia. Around the world Dutch naval units were responsible for transporting troops, for example during Operation Dynamo at Dunkirk and on D-Day, they escorted convoys and attacked enemy targets. Dutch submarines scored some victories, including one on a Kriegsmarine U-boat U-95 in the Mediterranean Sea, which was sunk by O 21, but during the war the Dutch Navy suffered heavy losses, particularly in the Pacific Theatre.