Marsha M. Linehan (born May 5, 1943) is an American psychologist and author. She is the creator of dialectical behavior therapy (DBT), a type of psychotherapy that combines cognitive restructuring with acceptance, mindfulness, and shaping.

Linehan is an Emeritus Professor of Psychology, Adjunct Professor of Psychiatry and Behavioral Sciences at the University of Washington in Seattle and Director of the Behavioral Research and Therapy Clinics. Her primary research is in borderline personality disorder, the application of behavioral models to suicidal behaviors, and drug abuse. Allen Frances, in the foreword for Linehan's book Building a Life Worth Living, said Linehan is one of the two most influential "clinical innovators" in mental health, the other being Aaron Beck.