Henry Knight "Heinie" Groh (September 18, 1889 – August 22, 1968) was an American third baseman in Major League Baseball who spent nearly his entire career with the Cincinnati Reds and New York Giants. He was the National League's top third baseman in the late 1910s and early 1920s, and captained championship teams with the 1919 Reds and 1922 Giants. Renowned for his "bottle bat", he was an effective leadoff hitter, batting .300 four times and leading the league in doubles twice and in hits, runs and walks once each.
He led the NL in double plays six times and in fielding percentage five times, both records, and in putouts three times; his .983 fielding average in 1924 was then a major league record, and remains the top mark in NL history. He set major league records for career fielding average (.967) and double plays (278), and upon retiring ranked third in NL history in games (1299) and assists (2554) and fourth in putouts (1456) and total chances (4146) at third base. His brother Lew played two games for the Philadelphia Athletics in 1919.