William Masters was an American obstetrician and gynecologist renowned for his pioneering work in the field of human sexuality and reproductive health. He is best known for co-founding the Masters and Johnson Institute along with Virginia Johnson, where they conducted groundbreaking research on sexual response cycles. Their studies revolutionized understanding of human sexuality, challenging many societal taboos and misconceptions. Throughout his career, Masters dedicated himself to studying the physiological aspects of sexual function and dysfunction. His work involved extensive experiments and observations, which contributed significantly to the development of sex therapy and treatment for sexual health issues. His contributions helped to destigmatize discussions about sexuality, paving the way for more open conversations and scientific inquiry. William Masters was born in 1915 in Cleveland, Ohio. He earned his medical degree from Ohio State University and specialized in obstetrics and gynecology. His groundbreaking research in human sexuality began in the 1950s, when societal attitudes toward sex were more conservative. His efforts not only advanced medical knowledge but also had a lasting impact on sex education and therapy, improving countless lives by providing a scientific foundation for understanding human sexual behavior.