Henry of Nassau-Siegen, German count, officer in the Dutch Army, diplomat for the Dutch Republic (born 1611)

Count Henry of Nassau-Siegen, German: Heinrich Graf von Nassau-Siegen, official titles: Graf zu Nassau, Katzenelnbogen, Vianden und Diez, Herr zu Beilstein, was a count from the House of Nassau-Siegen, a cadet branch of the Ottonian Line of the House of Nassau. He served the Republic of the United Netherlands in diplomatic missions, as an officer in the Dutch States Army, and as governor of Hulst.

1611 (MDCXI) was a common year starting on Saturday of the Gregorian calendar and a common year starting on Tuesday of the Julian calendar, the 1611th year of the Common Era (CE) and Anno Domini (AD) designations, the 611th year of the 2nd millennium, the 11th year of the 17th century, and the 2nd year of the 1610s decade. As of the start of 1611, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.

November 7 is the 311th day of the year in the Gregorian calendar; 54 days remain until the end of the year.