Robert Biswas-Diener (born July 27, 1972) is a positive psychologist, author and instructor at Portland State University. Biswas-Diener's mother is Carol Diener and his father is Ed Diener, both psychologists.

Biswas-Diener's research focuses on income and happiness, culture and happiness, and positive psychology. Biswas-Diener's research has led him to areas such as India, Greenland, Israel, Kenya, and Spain, and he has been called the "Indiana Jones of positive psychology". He obtained his PhD in 2009 on "Material wealth and subjective well-being" from the University of Tromsø. Biswas-Diener is interested in looking into the difference between a procrastinator and what he calls an "incubator".

Biswas-Diener is an author of books and articles and sits on the editorial boards of the Journal of Happiness Studies and Journal of Positive Psychology. Biswas-Diener also co-founded The Strengths Project, a charity whose mission is to "help underprivileged individuals and groups realise their strengths to enhance quality of life and build on their life circumstances."