Donald David "Donnie" Geisler III 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 City, Philippines before his retirement.