Claudine Alexandrine Guérin de Tencin (1681 - 4 December 1749) was a French courtesan and author.

Claudine was born in Grenoble, France where her father, Antoine Guérin, sieur de Tencin, was president of the parliament. Claudine was brought up at a convent near Grenoble and, at the wish of her parents, took the veil, but broke her vows and succeeded, in 1714, in gaining formal permission from the Pope Clement XI for her secularisation. She joined her sister Mme. de Ferriol in Paris, where she soon established a salon, frequented by wits and roués. Among her numerous lovers were the Chevalier Louis-Camus Destouches, the duc de Richelieu, and according to her biographer many other persons of distinction.

The last of her liaisons had a tragic ending. Charles-Joseph de la Fresnaye committed suicide in her house, and Mme. de Tencin spent some time in the Châtelet in consequence, but was soon liberated as the result of a declaration of her innocence by the Grand Consul. From this time she devoted herself to political intrigue, especially for the preferment of her brother the abbé Tencin, who became archbishop of Embrun and received a cardinal's hat. Eventually she formed a literary salon, which had among its habitués Bernard le Bovier de Fontenelle, Charles de Secondat, Baron de Montesquieu, Charles-Irénée Castel de Saint-Pierre, Pierre de Marivaux, Alexis Piron and others.

Hers was the first of the Parisian literary salons to which distinguished foreigners were admitted, and among her English guests were Henry St John, 1st Viscount Bolingbroke and Philip Dormer Stanhope, 4th Earl of Chesterfield. By the good sense with which she conducted what she called her menagerie, she almost succeeded in effacing the record of her early disgrace.

She was a novelist of considerable merit. Her novels have been highly praised for their simplicity and charm, the last qualities the circumstances of the writer's life would lead one to expect in her work. The best of them is Mémoires du comte de Comminges (1735), which appeared, as did the other two, under the name of her nephews, MM. d'Argental and Pont de Veyle, the real authorship being carefully concealed.

Her works, with those of Marie-Madeleine de La Fayette, were edited by Etienne and Jay (Paris, 1825); her novels were reprinted, with introductory matter by Lescure, in 1885; and her correspondence in the Lettres de Mmes. de Villars, de La Fayette et de Tencin (Paris, 1805-1832).