The Battle of Haarlemmermeer, a naval engagement in the Eighty Years' War.

The Battle of Haarlemmermeer was a naval engagement fought on 26 May 1573, during the early stages of the Dutch War of Independence. It was fought on the waters of the Haarlemmermeer – a large lake which at the time was a prominent feature of North Holland.

The Eighty Years' War or Dutch Revolt was an armed conflict in the Habsburg Netherlands between disparate groups of rebels and the Spanish government. The causes of the war included the Reformation, centralisation, excessive taxation, and the rights and privileges of the Dutch nobility and cities.

May 26 is the 146th day of the year in the Gregorian calendar; 219 days remain until the end of the year.