Mother of Tears (Italian: La Terza madre; lit. 'The Third Mother') is a 2007 supernatural horror film written and directed by Dario Argento, and starring Asia Argento, Daria Nicolodi, Moran Atias, Udo Kier and Coralina Cataldi-Tassoni. The film has also been billed in English-speaking media as Mater Lachrymarum, The Third Mother (English translation of the film's original Italian title) and Mother of Tears: The Third Mother.

Written by Argento, Jace Anderson and Adam Gierasch, the film is the concluding installment of Argento's supernatural horror trilogy The Three Mothers, preceded by Suspiria (1977) and Inferno (1980). The film depicts the confrontation with the final "Mother" witch, known as Mater Lachrymarum.