Josette Biyo was born on January 19, 1958, in Januiay, Iloilo. She earned her bachelor's degree in biological sciences from the University of the Philippines Visayas in Miagao, intending to continue to medical school. Instead, she took a teaching post and afterward earned a Ph.D. in biology from De La Salle University in Manila. Her dissertation examined seagrass community dynamics on Guimaras Island.