Charles II of Mecklenburg-Strelitz (German: Karl II. von Mecklenburg-Strelitz) (October 10, 1741 - November 6, 1816) was first duke, then grand duke of Mecklenburg-Strelitz.

Born in Mirow, he was the son of Prince Charles I Ludwig Frederick of Mecklenburg-Strelitz and Elisabeth Albertine of Saxe-Hildburghausen. At first he served as a Lieutenant General in the Hanoverian army. He later became governor of Hanover under his brother-in-law George III.

After his uncle Adolf Friedrich III died without any male descendants in 1752, Karl's older brother Adolf Friedrich IV became Duke of Mecklenburg-Strelitz. After he died childless in 1794, Karl II inherited the post.

Karl II encouraged new agricultural trends, established a new police force, and implemented compulsory education. In 1806, his duchy joined the Confederation of the Rhine. At the Congress of Vienna in 1815 his title was elevated, making him a grand duke.

Karl died on November 6, 1816 in Neustrelitz and was succeeded by his son Georg.

Karl married twice: first, to Friederike Caroline Luise of Hesse-Darmstadt, daughter of Prince Georg Wilhelm of Hesse-Darmstadt. They had ten children together. Two of them become German queen consorts. Louise would marry Frederick William III of Prussia and Frederica would marry Ernest Augustus I of Hanover. After she died in 1782, he married her sister Charlotte in 1784. She died in the following year, whilst giving birth to their son, Duke Karl Friedrich August.

*Duchess Charlotte (1769-1818) married Frederick, Duke of Saxe-Altenburg *Duchess Karoline Auguste (1771-1773) *Duke Georg Karl (1772-1773) *Duchess Therese (1773-1839) married Karl Alexander, Prince of Thurn and Taxis *Duke Friedrich Georg (1774-1774) *Duchess Louise (1776-1810) *Duchess Frederica (1778-1841) *Duke Georg (1779-1860) *Duke Friedrich Karl (1781-1783) *Duchess Auguste Albertine (1782-1782) *Duke Karl Friedrich August (1785-1837)

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