Gay Hendricks (born 1945) is a psychologist, writer, and teacher in the field of personal growth, relationships, and body intelligence.

Gay is best known for his work in relationship enhancement and in the development of conscious breathing exercises. After receiving his Ph.D. in psychology from Stanford University in 1974, Gay began teaching at the University of Colorado. He spent 21 years at the University of Colorado and became a Full Professor in the Counseling Psychology Department while founding The Hendricks Institute. He conducts workshops with his wife of more than 33 years, Dr. Kathlyn Hendricks. Together they have authored over 35 books. They have appeared on numerous radio and television shows, including an interview with radio host Jean Chatzky.

Hendricks co-founded The Spiritual Cinema Circle with his wife and producer Stephen Simon, was Executive Producer for the film Zen Noir (2004). He served as producer and writer on the Louise Hay movie, You Can Heal Your Life. In 2011, he partnered with writer Tinker Lindsey to begin the Tenzing Zorbu mystery series, with titles such as The First Rule of Ten and The Second Rule of Ten, which illustrate emotional and spiritual challenges in the life of a fictional ex-monk private detective. A short biopic was made of his life for Polish television, he was portrayed by Canadian actor, Jon Cubbon.