An eight-time All-Star, Smoltz was part of a celebrated trio of starting pitchers, along with Greg Maddux and Tom Glavine, who propelled Atlanta to perennial pennant contention in the 1990s, highlighted by a championship in the 1995 World Series.

Though predominantly known as a starter, Smoltz was converted to a reliever in 2001 after his recovery from Tommy John surgery, and spent four years as the team's closer before returning to a starting role.

He was named the Most Valuable Player of the 1992 NL Championship Series; Andy Pettitte later broke his record for career postseason wins.

Since 2016, he has provided color commentary during baseball's biggest televised events, notably the All-Star Game and World Series.

[citation needed] Following his high school career, Smoltz committed to play baseball at Michigan State University but elected to sign a professional contract after being drafted by the Detroit Tigers and receiving a substantial bonus offer.

[5] In 1987, the Tigers were in a three-team race, chasing the Toronto Blue Jays for the AL East division lead; in need of pitching help, Detroit sent their 20-year-old prospect to the Braves for 36-year-old veteran Doyle Alexander on August 12.

He began seeing a sports psychologist, after which he closed out the season on a 12–2 pace,[8] helping the Braves win a tight NL West race.

Both starters pitched shutout ball for seven innings, before Smoltz was removed from the scoreless game during a Twins threat in the eighth.

He left the seventh game trailing, but ended up with a no-decision as the Braves mounted a dramatic ninth-inning comeback win.

Before the 1993 season, the Braves signed renowned control pitcher Greg Maddux, completing — along with Smoltz and Glavine — what many consider to be the most accomplished starting trio ever assembled on a single major-league team.

Smoltz again won 15 games, but suffered his first postseason loss to the Philadelphia Phillies in the NLCS despite not allowing an earned run.

Smoltz continued to post excellent statistics in 1998 and 1999, but he was spending significant time on the disabled list and missed about a quarter of his starts.

[12] When he was unable to perform effectively as a starter in 2001, Smoltz transitioned to the bullpen, replacing John Rocker as the Braves' closer.

In 2002, his first full season as a closer, Smoltz set a National League record with 55 saves, topping the previous mark of 53, shared by Randy Myers (1993) and Trevor Hoffman (1998).

Smoltz finished third in the Cy Young Award voting; Éric Gagné equaled his record a year later with the Dodgers.

In 2004, Smoltz finished with 44 saves, but was frustrated with his inability to make an impact as a closer during another Braves' postseason loss.

Smoltz gave up a solo home run to Miguel Tejada in the second inning of the American League's 7–5 victory and was charged with the loss.

On August 19, Smoltz set the Braves strikeout record by striking out the Arizona Diamondbacks' Mark Reynolds.

[18] In December 2008, several members of the Boston Red Sox organization, including pitching coach John Farrell, vice president of player personnel Ben Cherington and assistant trainer Mike Reinold, flew to Atlanta to participate in a 90-minute workout with Smoltz.

He was designated for assignment on August 7 after a 13–6 loss to the New York Yankees, giving the Red Sox ten days to release or trade him, or send him to the minors.

In Game 3 of the 2009 NL Division Series, Smoltz pitched two innings of relief in a losing cause, allowing four hits and an earned run while striking out five.

Smoltz was forced to end his in-studio work for MLB Network after he refused to receive the COVID-19 vaccine, which is required for the company's employees.

[33] The ceremony, which took place before a June 8 game against the Toronto Blue Jays, included speeches by former broadcaster Pete van Wieren, former teammate Matt Diaz and former manager Bobby Cox.

Smoltz met his first wife, Dyan Struble, at the Omni Hotel in downtown Atlanta; the couple had four children before divorcing in 2007 after 16 years of marriage.

[44] Smoltz produced an automated campaign phone recording on behalf of the candidacy of Ralph E. Reed, Jr. for Lieutenant Governor of Georgia during the 2006 primary.

[46] It was speculated that Smoltz might run for Congress in 2010 as a Republican candidate to fill the departing John Linder's seat in Georgia's 7th congressional district.

[47] On April 22, 2012, Smoltz hosted a fundraiser for Andrea Cascarilla, a Democratic candidate for State Representative in Michigan's 71st House District.

[49] Smoltz is the Atlanta host for Big League Impact, an eight-city fantasy football network created and led by longtime Cardinals pitcher and former teammate Adam Wainwright.

[50] Smoltz and fellow former Atlanta Braves first baseman Ryan Klesko were named in a tax dispute involving conservation easement for a 1,546-acre non-cash donation the two made on behalf of a partnership the two formed in the early 1990s.

[51] On 25 April 2024, the court cleared the two of fraud charges, but reduced the assessed value of the donated easement to one-tenth of the claimed amount, and imposed a 40% penalty.