The Giants left-hander is the 24th member of the 300-win club and just the sixth southpaw. He accomplished the mark with a dominating career in which he has compiled the second-most strikeouts in history behind only Nolan Ryan.
Johnson won his first Cy Young Award with the Mariners in 1995 and his most recent one with the D-backs in 2002. It was the last one that showed just how driven Johnson was.
Following his third straight Cy Young Award and a 2001 World Series co-Most Valuable Player Award -- and already regarded as one of the game's all-time greats -- Johnson showed up at Spring Training in 2002 and told reporters that he felt he could still improve. Remarkably, he did just that, putting together his best statistical season and leading Arizona to its third NL West title in four seasons.
Here is a recap of Johnson's Cy Young seasons:
1995: Johnson picked up his first Cy Young Award by securing 26 of 28 first-place votes. He won 18 games against just two losses, but none of the wins were as big as the three-hit complete game he tossed in a one-game playoff against the Angels. His .900 winning percentage broke Ron Guidry's AL mark for winning percentage in a season.
The Mariners were 27-3 in games started by Johnson and he equaled a career-high by throwing 160 pitches in a complete-game victory against the Indians. Down the stretch when the Mariners needed him the most, Johnson was 7-0 with a 1.45 ERA over his final 10 starts.
Johnson won Game 3 of the Division Series against the Yankees and returned on one day's rest to fan six in three innings of relief work as the Mariners won Game 5 to advance to the AL Championship Series.
1999: Johnson joined Gaylord Perry and Pedro Martinez as the only pitchers to that point to win a Cy Young Award in both leagues. In his first year in Arizona, he threw a career-high 271 2/3 innings and helped the D-backs win 100 games and the NL West in just their second year of existence.
His record was 17-9, but should have been much better as he lost four straight starts in which he compiled a 1.41 ERA. In the four games, the D-backs were no-hit, one-hit, two-hit and three-hit in succession.
Johnson was a strikeout machine, fanning 364 batters, including 23 games of 10-plus strikeouts, while leading the league with 12 complete games.
2000: Johnson became the third National League pitcher to win consecutive Cy Young Awards and the first left-hander to do it since Sandy Koufax in 1965-66. He reached the 3,000-strikeout plateau when he struck out Mike Lowell on Sept. 10 at Florida.
Johnson struck out 347 to lead the Majors and became the second pitcher in history to fan 300-plus batters in three consecutive seasons. He tied for the NL lead in complete games (eight), shutouts (three) and starts (35) while leading the league in winning percentage (.731).
With a 15-2 record and a 2.01 ERA at the All-Star break, Johnson was named the NL starter in the Midsummer Classic.
2001: Johnson struck out a career-best 372 in 249 2/3 innings, the first time a pitcher had recorded 300 strikeouts in four consecutive seasons. His strikeouts per nine innings ratio of 13.4 was the best single-season mark in Major League history and he came within 11 strikeouts of Nolan Ryan's all-time mark.
Johnson tied a Major League record when he fanned 20 Reds on May 8, in Phoenix. He also set a record for strikeouts by a reliever with 16 when he threw seven innings when a suspended game against the Padres was resumed one day later. Down the stretch, with the D-backs battling for the NL West title, Johnson was 16-2 with a 2.21 ERA in his last 24 appearances and 12-1 in his final 13 decisions.
In the playoffs he was outstanding, going 5-1 with a 1.52 ERA in six games (five starts) as the D-backs became the quickest expansion franchise to win a World Series. Johnson won three games (Games 1, 6 and 7) in the World Series against the Yankees. He pitched in relief in Game 7 one night after throwing seven innings, the first pitcher in 55 years to come out of the bullpen in such a manner.
2002: Arguably the most impressive season of his career, Johnson captured the "Triple Crown" of pitching by leading the NL in wins (24), ERA (2.32) and strikeouts (334). It was the second time in NL history that a pitcher had accomplished that feat -- Dwight Gooden did so in 1985. Jake Peavy joined the elite group in 2007.
Johnson became the first pitcher in big league history to fan 300 or more batters in five straight seasons. He started the year with a 6-0 April and finished with a 5-0 September as the D-backs won the NL West again.
He continued his climb up the all-time strikeout list that year, moving from ninth to fourth while passing Walter Johnson, Perry, Don Sutton, Tom Seaver and Bert Blyleven.
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.