She was born Sophia Charlotte, at Mirow in her father's duchy of Mecklenburg-Strelitz, Germany. Having been selected as the bride of the young king George (who had already flirted with several young women considered unsuitable by his mother, Augusta of Saxe-Gotha, and by his political advisors), she arrived in Britain in 1761 and the couple were married at the Chapel Royal in St James's Palace, London, on September 8 of that year.
Despite not having been his first choice, and having been treated with a general lack of sympathy by his mother, Charlotte's relationship with her husband soon blossomed, and he is not known ever to have been unfaithful to her. In the course of their marriage, they had sixteen children, most of whom survived into adulthood. Charlotte was supportive to her husband as he descended into mental illness, but pre-deceased him, dying at Kew Palace, their family home in Surrey. She was buried at Windsor.
Queen Charlotte was a descendant, through six lines, of Margarita de Castro y Sousa, a black, Moorish, or mixed-race member of the Portuguese royal family who lived in the 15th century. Charlotte's biographer Olwen Hedley states that Queen Charlotte's personal physician, Christian Friedrich, Baron von Stockmar, described his patient as having "true mulatto features" ("ein wahres Mulattengesicht").