Antonio Pimentel de Prado y lo Bianco (Palermo, 1604 - Antwerp (c. 1671-72) was a Spanish officer, a governor of Nieuwpoort (1646–1651), ambassador in Stockholm (1652–1654), Knight of the Order of Santiago (1658), representative in Paris (1659), governor of Cadiz (1660–1670), and at the end of his life counsel and chief of the army in Antwerp (1670–1672).
About his youth is not much known. His father Lorenzo Pimentel Prado served at the court of the Duke of Bivona in Palermo and had three sons: Juan, Antonio and Gregorio. His nephew Bernardino de Rebolledo appointed Antonio Pimentel del Prado as the Spanish ambassador in Sweden. This was the first Spanish mission to Sweden since the reign of John III of Sweden.
Christina, Queen of Sweden, began in 1651 negotiations with Philip IV of Spain and had the Swedish diplomat Matthias Palbitzki sent to the Spanish court. Philip IV who was looking for good relations had ordered the Spanish diplomat to promote Swedish interests anywhere in Europe. The aim of the embassy in Stockholm was officially to investigate the military power of Sweden, but the main task was to find out whether the queen had no wedding plans, because the balance of power in Europe would be severely affected if Christina married someone hostile to the power of Spain.
Don Antonio Pimentel arrived in Dalarö on August 12, 1652, along with his wife, children and an entourage of 50 people, to appear in Stockholm on 16 August. Already on August 19 he was received by the queen. The gallant Pimentel quickly became her confidant. He tried to obtain support for her proposal to abdicate. Christina and Pimentel began secret negotiations, often condducted in her library which gave rise to rumors. She gave him an insight into her plans for the future after abdication.
Pimentel departed after asking for a large portrait of the Queen as a gift to the King of Spain. This painting by Sebastien Bourdon was finished in June 1653 and now hangs in the Prado. The Queen appointed him in early August before his departure a knight of the Amaranthen Order. All members had to promise never to marry again or not at all; (the order was dissolved in 1654).When he left Gothenburg, his ship leaked and he was forced to return. Pimentel went with the queen to Östergötland and followed her to Stockholm. Until June 1654, when there was nothing to stand in the way of her conversion Christina abdicated. She left her country for the Spanish Netherlands to embrace the Catholic faith. Christina continued her friendship with Pimentel, partly because Christina wanted to mediate, between France and Spain who were involved in the Franco-Spanish War (1635-1659).