Jean-Baptiste de Boyer, Marquis d'Argens (24 June 1704 – 11 January 1771) was a French rationalist, author and critic of the Catholic Church, who was a close friend of Voltaire and spent much of his life in exile at the court of Frederick the Great.

Jean-Baptiste rejected a legal career and while the rest of his family were devout Catholics, became a rationalist author and critic of the Church; he later wrote 'I was not my father's favourite child.

[6] After many years living in Berlin, he returned to France in 1769, where he died at the Château de La Garde on 11 January 1771; originally buried in Toulon Cathedral, his remains were later moved into the family vault at Le Couvent des Minimes.

One of his warders was Vicomte d'Andrezel, shortly to become French ambassador in Constantinople; he persuaded Pierre-Jean de Boyer to allow his son to accompany him and they left Toulon at the end of 1723.

This was followed by Lettres juives, issued in six volumes between 1736 and 1740; employing the format used by Montesquieu in his 1721 work Persian Letters, this was an immediate success but provoked criticism from Catholic writers such as de La Martinière.

He was also appointed Director of the Belles-Lettres section of the Prussian Academy of Arts and of the Berlin State Opera; it was while visiting Paris to recruit performers that he met Babette Cochois, whom he married in 1749.

[7] D'Argens was part of the mid-18th-century Enlightenment movement in France, led by Voltaire, Jean-Jacques Rousseau and Montesquieu, who argued for a society based on reason, rather than faith, and the separation of church and state.