The Welsh Greyhound Derby was a former classic greyhound competition held in Wales.

Mick the Miller was a male brindle greyhound. He is celebrated as the first great racing greyhound to compete in England. Despite a short three-year racing career, his achievements were highly publicised around the world and by the end of his career he had become an icon in the sport. His achievements include winning nineteen races in a row, including the English Greyhound Derby on two successive occasions. He suffered an injury at Wimbledon Stadium whilst racing which broke the streak in 1931, and once recovered was beaten in the attempt to win a third Derby title. He went on to appear in films, and is still considered one of the greatest sporting heroes in the UK.