Joseph-Siffred Duplessis
(22 September 1725 – 1 April 1802) was a French painter, known for the clarity and immediacy of his portraits.
He was born in Carpentras, near Avignon, into a family with an artistic bent and received his first training from his father, a surgeon and talented amateur.
He subsequently studied with Joseph-Gabriel Imbert (1666–1749), who had been a pupil of Charles Le Brun.
From 1744–47 or later he worked in Rome, in the atelier of Pierre Subleyras (1699–1749), who was also from the south of France.
He continued to exhibit at the Paris salons, both finished paintings and sketches, until 1791, and once more, in 1801.
His portrait of the Dauphine in 1771 and his appointment as a peintre du Roi assured his success: most of his surviving portraits date from the 1770s and 1780s.
He received privileged lodgings in the Galeries du Louvre.
In the Revolution, he withdrew to safe obscurity at Carpentras during the Reign of Terror.
Afterwards, from 1796, he served as curator at the newly founded museum formed at Versailles, so recently emptied of its furnishings at the Revolutionary sales.