Doña Carlota Joaquina of Spain (Carlota Joaquina de Borbón y Borbón-Parma; 25 April 1775 – 7 January 1830) was a Queen consort of Portugal as wife of John VI, Infant of Spain, Infant consort of Portugal, Princess consort of Brazil, Princess regent consort of Portugal and Queen consort of the United Kingdom of Portugal, Brazil and Algarves. She was the eldest daughter and surviving child of King Charles IV of Spain and his wife Maria Luisa of Parma.

She was born in Aranjuez during the reign of her paternal grandfather, Charles III of Spain, the eldest surviving child born to her parents. Her father was the second son of Charles III and his wife Maria Amalia of Saxony; her mother, Maria Luisa of Parma was a granddaughter of Louis XV of France through her mother Princess Louise Élisabeth of France. Louise Élisabeth's husband Philip, Duke of Parma, was a younger brother of Charles III. Carlota Joaquina's future husband was a grandson of Mariana Victoria of Spain, sister of Charles III and the Duke of Parma.

The subject of Carlota Joaquina's marriage was arranged by Mariana Victoria and Charles III in the late 1770s when Mariana went to Spain to encourage diplomatic relations between the estranged countries. Carlota Joaquina was to marry the future John VI of Portugal (at that time only an Infante of Portugal), and Carlota Joaquina's uncle Infante Gabriel was to marry the Infanta Mariana Vitória of Portugal, another grandchild of Mariana Victoria of Spain.

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