Although Mazzone was born in West Virginia, his family lived on the other side of the Potomac River's north branch in Luke, Maryland.

Growing up there, one of his friends was Sam Perlozzo of nearby Cumberland, Maryland, under whom Mazzone would eventually coach for the Baltimore Orioles.

It was the recommendation and contacts of Eagles owner Ray Kuhlman that proved instrumental in Atlanta deciding to take a chance on Mazzone in 1979.

[citation needed] Mazzone has earned a reputation as one of the best pitching coaches of the modern era,[1] having molded Tom Glavine and John Smoltz into perennial All-Stars.

[3] This dominant pitching anchored the Braves' run of 14 consecutive division titles (1991-2005), 5 National League pennants (1991-1992, 1995-1996, 1999) and the 1995 World Series championship.

Between 1991 and 1998, three of his pitchers won a total of 6 Cy Young Awards: Maddux, Glavine, and Smoltz have all been inducted into the National Baseball Hall of Fame.

[4] On August 30, 2016, Leo Mazzone was hired by Head Coach Brett Harker of the Furman University Baseball program as a Special Pitching advisor.