Henry John Gruber (December 14, 1863 – September 26, 1932) was an American professional baseball pitcher who played from 1885 through 1895.

He was also the first professional coach hired by the Yale University baseball team, holding that position in 1892.

He began his professional baseball career at age 21, playing for the Hartford Babies of the Southern New England League.

[2] His 2.74 ERA was the lowest on a team that won the National League pennant and went on to defeat the St. Louis Browns in the 1887 World Series.

In December 1888, the Cleveland Spiders purchased Gruber, Ed Beatin, Sy Sutcliffe and Larry Twitchell from the Wolverines.

The Spiders in February 1890 attempted, unsuccessfully, to induce Gruber to disregard his contract with the Players' League and return to the Spiders, as reflected in this report from Sporting Life:"A dispatch from New Haven, Conn., states that Secretary Hawley, of the Players, has recently been in that city to induce pitcher Henry Gruber, who has signed with the Cleveland Players' League, to throw up his contract with the Brotherhood.

Gruber refuses to do this and will stand by the Brotherhood, although he is dissatisfied with the contract he has signed with them, owing to the clause which provides that a player's salary shall not be paid unless the gate receipts are enough to meet the expenses.

[2] In his Players' League debut, Gruber walked 16 batters in a 23-2 loss to the Buffalo Bisons.

[2] In 1892, while still under contract with Cleveland, Gruber was hired as the first professional coach of the Yale University baseball team.

[8][9][10] Shortly after he was hired, in late March 1892, Gruber was hit in the ankle by a batted ball while training the players in Yale's gymnasium.