Donald David "Donnie" von Geisler III (born October 6, 1977) is a retired Filipino taekwondo athlete of German-American descent, who represented the Philippines in the Summer Olympic Games in the years 2000 and 2004. He is a 1998 Asian Games and World Cup Taekwondo Silver medalist, and won a gold medal for the men's lightweight division at the 2005 Southeast Asian Games held in Pasay, Philippines before his retirement.

Geisler started playing taekwondo at the age of seven. He was trained by a Korean trainer at school where he developed his skills for the sport.^{[citation needed]}