Louis John DiMuro (b. April 24, 1931 in Brooklyn, NY – d. June 7, 1982 in Arlington, TX) was an umpire in Major League Baseball who worked in the American League from 1963 until his death in 1982. He worked the 1969 and 1976 World Series and the 1965, 1967, 1972, and 1981 All-Star games.

Notably, In Game 5 of the 1969 World Series, the New York Mets held a 3 games to 1 lead over the heavily favored Baltimore Orioles, and were looking to close the series at home in front of a raucous crowd at Shea Stadium. The Orioles, behind the pitching of ace Dave McNally, led 3–0 in the bottom of the sixth inning when a pitch from McNally was low and inside to Mets leadoff hitter Cleon Jones. DiMuro, the home plate umpire, called the pitch a ball, but New York manager Gil Hodges appealed the ruling, believing the pitch hit Jones.

Hodges showed the ball to Lou, and pointed out a speck of black shoe polish. DiMuro accepted Hodges' explanation, and awarded Jones first base. Baltimore manager Earl Weaver, who had been ejected from Game 4 by umpire Shag Crawford for arguing balls and strikes, immediately came out and vehemently protested the decision, to no avail. The next Mets batter Donn Clendenon hit a two run HR bringing New York within a run. The rest is Mets history.

He was walking down the street after calling a Texas Rangers/Chicago White Sox game on June 6, 1982, when he was hit by a car. He died a day later.

Lou was also an umpire in the Kitty League (1955), Northern League (1956), Eastern League (1957), and International League (1958-1962) and served in the Air Force in West Germany.

He is the father of MLB umpires Ray and Mike DiMuro.

(excerpted from Centerfield Maz, Baseball Almanac, BR Bullpen & Wikipedia)