Donald David von Geisler III is a taekwondo athlete who represented the Philippines in the 2000 Summer Olympics in Sydney, and the 2004 Olympics in Athens. He is of German and American descent.
Born in Angeles, Pampanga, Geisler started playing taekwondo at 7. He studied under a Korean trainer. In 1996, he won the bronze medal in the 1st World Junior Taekwondo Championships. He bagged two silvers in the Bangkok Asian Games and the World Cup Taekwondo in 1998. In 1999, he was the gold medalist for the 20th Southeast Asian Games. In the 21st Southeast Asian Games in 2001, Geisler bagged the silver medal. He was able to win the gold prize in the 23rd and 25th Southeast Asian Games respectively.