Glavine attended Billerica Memorial High School, where he was an excellent student and a letterman in ice hockey as well as baseball.

In hockey, he scored 47 goals and 47 assists in 23 high school games, and as a senior, he was named the Merrimack Valley's Most Valuable Player.

[3] Glavine was the ace of the 1991 Braves' starting rotation that included Steve Avery, Charlie Leibrandt, and another future NL Cy Young Award winner and Hall of Fame inductee, John Smoltz.

His season helped ensure a dramatic reversal in the Braves' competitive fortunes as they won the National League pennant and earned a trip to the World Series, though they lost to the Minnesota Twins in seven games.

Atlanta, long thought of as a perennial cellar dweller, was lifted in the 1990s into one of the most successful franchises in the game on the strength of its stellar pitching staff and solid hitting.

Years later, after Glavine joined the Mets and Maddux played for the San Diego Padres, the three (along with Smoltz who still pitched for Atlanta) all recorded wins on the same day, June 27, 2007.

Glavine's performance had slumped in the second half of 2002 and he was ineffective in his two postseason starts, so Atlanta refused to guarantee a third year on his contract.

Glavine did get to enjoy a personal highlight at the end of the season, however, when the Mets called up his brother Mike to join the team.

Glavine began 2004 well, highlighted by a May 23 one-hit shutout of the Colorado Rockies[4] and selection to the National League All-Star team.

The results of that new test showed the problem could be treated with medicine, and Glavine resumed pitching on September 1, against the Houston Astros.

Glavine finished the 2006 season with a fine 15–7 record and a 3.82 ERA, as the Mets won the National League Eastern Division, allowing him to make his first playoff appearance since leaving the Braves.

He then started Game 1 of the National League Championship Series against the St. Louis Cardinals, pitching seven shutout innings to pick up the win, helped by Carlos Beltrán's two-run home run.

[3] On August 5, 2007, Glavine won his 300th game, against the Chicago Cubs at Wrigley Field on ESPN's Sunday Night Baseball.

Glavine made one of the worst starts of his career, allowing seven runs while recording only one out, and the Mets were eliminated from playoff contention with an 8–1 loss.

[9] Glavine declined a one-year, $13 million contract option for the 2008 season with the Mets on October 5, 2007, ending his tenure with the team.

[10] On November 18, 2007, Glavine rejoined the Braves, seemingly bringing his career full circle, with a one-year contract worth $8 million.

On the date of his retirement, Glavine agreed to take a job as a special assistant to Braves president John Schuerholz starting in the 2010 season.

Even at the end of his career, he was an effective starting pitcher in the National League due to his excellent control and deception, changing speeds, and locating pitches off the outside corner of the strike zone.

Glavine's consistency was also highlighted by his durability; beginning with his first full year, in 1988, he started at least 25 games every season and was never placed on the disabled list until his final season—at age 42.

He had a good eye, drawing a high number of walks (for a pitcher), which, combined with his hits, gave him a career on-base percentage of .244.

Prior to and during the 1994–95 Major League Baseball strike, Tom Glavine was heavily involved in negotiations between the union and team owners and was frequently interviewed and quoted in the press about the talks.

When play resumed in 1995, Glavine was frequently booed by Braves fans for his role in the players' union and was criticized for it in the local Atlanta press.