Adolph G. "Ade" Sieberts (August 29, 1893 – April 28, 1968) was an American basketball player, known best for his college career where he was Oregon State University's first All-American in the sport. Sieberts, a forward from Portland, Oregon, went to Oregon Agricultural College (now Oregon State University) where he played basketball and baseball. As a basketball player, he led the Aggies to a Pacific Coast Conference (now known as the Pac-12 Conference) championship and was named first-team all-conference. He was also named an All-American by the Helms Athletic Foundation for his 1915–16 junior season.