Henry Girard Ostdiek (April 12, 1881 – May 6, 1956) was a reserve catcher in Major League Baseball who played for the Cleveland Naps (1904) and Boston Red Sox (1908) during his major league career. Listed at 5 ft 11 in (1.80 m), 185 pounds (84 kg), Ostdiek batted and threw right-handed. He was born in Ottumwa, Iowa.
In an eight-game career, Ostdiek was a .143 hitter (3-for-21) with three RBI, one run, and one triple without a home run. In eight catching appearances, he posted a .935 fielding percentage, committing three errors in 46 chances.
Ostdiek died at the age of 75 in Minneapolis, Minnesota.