The Sin of Madelon Claudet is a 1931 American pre-Code drama film directed by Edgar Selwyn and starring Helen Hayes.

When neglected wife Alice (Karen Morley) decides to leave her doctor husband Lawrence (Robert Young), his friend Dr. Dulac (Jean Hersholt) stops her and tells her the life story of another woman, the French Madelon Claudet (born May 7, 1878) (Helen Hayes), who was persuaded by her American boyfriend, artist Larry Maynard (Neil Hamilton), to run away with him.

She becomes the mistress of an older acquaintance, Count Carlo Boretti (Lewis Stone), while her friends Rosalie (Marie Prevost) and Victor Lebeau (Cliff Edwards) care for the boy.

Madelon is determined to finance Lawrence's medical education, but with the end of World War I, millions of Frenchmen are released from the army and jobs are scarce.

Aged and destitute, she decides to give up her freedom and commit herself to state charity, but visits her son one last time, pretending to be a patient.

When she leaves, she encounters Dr. Dulac, who recognizes her and persuades his friend Dr. Claudet, still unaware of her true identity, to provide for her.

In his review in The New York Times, Mordaunt Hall wrote "[Helen Hayes'] superb portrayal in a difficult role leaves only the regret that the powers that be did not see fit to have her make her screen début in a more cheerful study...The Sin of Madelon Claudet is a sorrowful chronicle which will undoubtedly have a strong popular appeal.