The tradition of eating fish on Good Friday is believed to have originated in medieval Europe. During the Middle Ages, Catholics were prohibited from eating meat on Fridays as a form of penance and self-discipline. However, they were allowed to consume fish, which was seen as a symbol of life and abundance due to its association with water and fertility.
Over time, the practice of abstaining from meat and eating fish on Good Friday became a part of the religious observances associated with the holiday. The popularity of fish as a Good Friday meal also spread to non-Catholic communities and became a cultural tradition in many countries around the world.