Henry Clyde Day (August 26, 1899 – March 21, 1934) was a champion Arkansas hog-caller and right-handed pitcher in Major League Baseball who committed suicide after an unsuccessful operation to repair his throwing arm.

Also known for his screwball pitch and his eccentric personality, Day was described in his obituary as "a care-free, fun-loving figure who gave the game one of its most widely known characters.

"[1] Day began his pitching career playing in the minor leagues for Joplin, Fort Smith, Little Rock, and Muskogee from 1921 to 1924.

He made his major league debut in September 1924 with the St. Louis Cardinals, starting three games and going 1–1 in 17-2/3 innings with a 4.58 earned run average.

The Cardinals sent him to the minor leagues in Syracuse, and from there he signed for the 1926 season with the Cincinnati Reds, where he appeared in four games and 7-1/3 innings with a 7.36 earned run average.

[1] Desperate to revive his pitching career, Day went to the world-renowned Mayo Clinic in Rochester, Minnesota for a delicate and expensive operation to restore his arm.

Day reportedly turned to alcohol and in March 1934, traveled to Kansas City, "seeking treatment for lapses of memory."

On March 21, while staying in the apartment of former teammate Max Thomas, Day slit his throat with a hunting knife.