Orie Edgar Arntzen (October 18, 1909 – January 28, 1970) was an American professional baseball pitcher. He played in Major League Baseball (MLB) for the Philadelphia Athletics during the 1943 season. Listed at 6 feet 1 inch (1.85 m) and 200 pounds (91 kg), he threw and batted right-handed.

Arntzen played in Minor League Baseball between 1933 and 1952; records for several of his seasons are incomplete.^[1] For seasons with records available, he had a win–loss record of 192–93, including a 25-win season with the Albany Senators of the Eastern League in 1949.^[1] His performance was recognized with The Sporting News Minor League Player of the Year Award.^{[citation needed]} He pitched for farm teams of the St. Louis Cardinals, Cleveland Indians, Philadelphia Athletics, and Pittsburgh Pirates.^[1]

Arntzen's only season in Major League Baseball was 1943, when he appeared in 32 games (20 starts) for the Athletics.^[2] In 164+1⁄3 innings pitched, he struck out 66 batters while compiling a 4–13 record with a 4.22 earned run average.^[2] As a batter, he had eight hits in 50 at bats for a .160 batting average.^[2] In late September, he was traded to the Pirates for fellow pitcher Luke Hamlin, but would not pitch in MLB again.^[2]

Nicknamed "Old Folks", Arntzen died in 1970, aged 60, reportedly of a heart attack after being ill with kidney issues.^[3]