Herbert Sidney Langfeld (July 24, 1879 – February 25, 1958) was an American psychologist and a past president of the American Psychological Association (APA).

Herbert Langfeld was born in Philadelphia on July 24, 1879.^[1] He grew up in Philadelphia and was initially drawn to a diplomatic career. He was working for the American Embassy in Berlin when he was attracted to psychology. He earned a PhD in 1909 at the University of Berlin. He took a faculty position at Harvard University and ultimately went to Princeton University, where he became the psychological laboratory director and later the department chair for psychology.^[2] While at Princeton he also directly influenced the ecological psychology approach of J. J. Gibson through his phenomenological ideas.^[3]

Langfeld was APA president in 1930.^[4] He also held leadership positions with the International Congress of Psychology and the Psychology Section of the American Association for the Advancement of Science.^[5]

He died from heart disease in Princeton, New Jersey on February 25, 1958.^[6]