Larry Wayne Vanover is an American professional baseball umpire. Vanover worked in the National League from 1991 to 1999. He did not umpire in 2000 and 2001, and since 2002 has umpired across both major leagues. Vanover has umpired two All Star Games, and in the 2016 World Series. He was promoted to crew chief in 2015. Vanover wore sleeve number 28 during his National League tenure, then changed to 27 after his return to the MLB umpiring staff in 2002.

In baseball, the umpire is the person charged with officiating the game, including beginning and ending the game, enforcing the rules of the game and the grounds, making judgment calls on plays, and handling the disciplinary actions. The term is often shortened to the colloquial form ump. They are also sometimes addressed as blue at lower levels due to the common color of the uniform worn by umpires. In professional baseball, the term blue is seldom used by players or managers, who instead call the umpire by name. Although games were often officiated by a sole umpire in the formative years of the sport, since the turn of the 20th century, officiating has been commonly divided among several umpires, who form the umpiring crew. The position is analogous to that of a referee in many other sports.