Maddux was born in San Angelo, Texas, and spent much of his childhood in Madrid, Spain, where the United States Air Force stationed his father.

Upon his return to Las Vegas, Nevada, Maddux and his brother Mike, who became a pro player himself, trained under the supervision of Ralph Meder, a former scout from the majors.

Mapson wrote a glowing review that read in part, "I really believe this boy would be the number one player in the country if only he looked a bit more physical.

In the bottom of the third inning, Padres starter Eric Show hit Cubs star Andre Dawson in the face with a pitch and triggered a bench clearing brawl.

Manager Don Zimmer tabbed him to start Game One of the National League Championship Series against the San Francisco Giants.

After consecutive 15-win seasons in 1990 and 1991, Maddux won 20 games in 1992, tied for the NL lead, and was voted his first National League Cy Young Award.

Both Chicago general manager Larry Himes and Maddux's agent, Scott Boras, accused the other of failing to negotiate in good faith.

The Cubs eventually decided to pursue other free agents, including José Guzmán, Dan Plesac, and Candy Maldonado.

[18] Maddux made his debut with the Braves on April 5, 1993, as their opening day starter against the Cubs at Wrigley Field, beating his former teammates 1–0.

[19] He finished the regular season with a 20–10 record, led the NL with a 2.36 ERA, and won his second straight Cy Young Award.

During the strike-shortened 1994 season, Maddux posted an ERA of 1.56, the second-lowest since Bob Gibson's historic 1.12 in 1968, the last year of the elevated mound, and the lowest in the majors since Dwight Gooden's 1.53 in 1985.

His Game One victory in the 1995 World Series involved nine innings, two hits, no walks, and no earned runs with Orel Hershiser pitching for the Cleveland Indians.

The Atlanta Braves also made good on a pre-season promise to their pitching rotation, installing a putting green in the locker room at the newly built Turner Field following the World Series victory.

Three weeks earlier, he had shut out the defending champion New York Yankees on 84 pitches, and five days before that he had beaten the Phillies with a 90-pitch complete game.

[23] In July and August of that year, Maddux pitched 721⁄3 consecutive innings without giving up a walk; that streak ended when he intentionally threw four balls to Steve Finley.

The three pitchers were frequently augmented by other strong starters such as Steve Avery, Kevin Millwood, Denny Neagle, and Russ Ortiz.

On September 30, 2006, Maddux pitched seven innings in San Francisco, allowing two runs and three hits in a 4–2 victory over the Giants, clinching a postseason spot for the Dodgers and notching another 15-win season.

It was Maddux's 18th season among his league's Top 10 for wins, breaking a record he'd shared with Cy Young and Warren Spahn, who did it 17 times apiece.

[30] Maddux was traded back to the Los Angeles Dodgers on August 19 for two players to be named later or cash considerations by the San Diego Padres.

[31] His return to Los Angeles was unlike his debut, though, as he allowed 7 earned runs on 9 hits while taking a loss against the Philadelphia Phillies.

On September 27, in his final start of the season, he won his 355th game, moving him ahead of Roger Clemens into 8th place in all-time wins.

[32] After the Dodgers won the National League West, Maddux was moved to the bullpen after manager Joe Torre decided to go with a three-man rotation.

In his return to Chicago, his focus was on developing pitchers' styles and techniques throughout the organization, including minor league affiliates.

[36] For the 2012 season Maddux left his position with the Cubs and joined the Texas Rangers organization, where his brother Mike was the pitching coach.

Though his fastball touched 93 mph in his early years,[41] his velocity steadily declined throughout his career, and was never his principal focus as a pitcher.

[42] Maddux was also noted for the late movement on his sinker (two-seam fastball), which, combined with his control, made him known as an excellent groundball pitcher.

On July 2, 1997, he won a game against the New York Yankees, for example, with the numbers "nine innings, three hits, no walks, eight strikeouts, one pickoff, one double play, 84 pitches ... [in] two hours and nine minutes".

[56] On another occasion while sitting on the bench, Maddux once told his teammates, "Watch this, we might need to call an ambulance for the first base coach."

Maddux explained: "I remember that one because he got a hit off me in the same situation (full count, bases loaded, two out in the 9th inning) seven years earlier.

[70] In 2002, in the episode "Take Me out of the Ballgame", of the TV series Do Over, the main character lost a baseball game to a young Greg Maddux, who was played by Shad Hart.