Gonzalez grew up in the West Tampa neighborhood of Tampa, Florida. He graduated from Thomas Jefferson High School in 1985 along with childhood friend Tino Martinez. After high school, he attended the University of South Alabama, where he earned Baseball America's All-Freshman Second Team honors. He was drafted by the Houston Astros in the fourth round of the 1988 amateur draft. Gonzalez played American Legion Baseball for Post 248. Other Post 248 alumni include Lou Piniella, Tony La Russa, Tino Martinez and Gary Sheffield.
Gonzalez made his major league debut on September 4, 1990. He finished the rest of the 1990 season with 4 hits (2 doubles). The year of 1991 became the first full season of Gonzalez's career. During 1991, he batted .254 with 13 home runs and 69 RBI. In 1992, he batted .243 with 10 home runs and 55 RBI. In 1993, he batted .300 with 15 home runs, 72 RBI, and an NL leading 10 sacrifice flies. In 1994, he batted .273 with 8 homers and 67 RBI. His 1995 season began with a .258 batting average, 6 homers and 35 RBI.
Gonzalez along with Scott Servais were traded to the Chicago Cubs for Rick Wilkins. Gonzalez finished the 1995 season with the Cubs by batting .290 with 7 homers and 34 RBI. Overall in 1995, Gonzalez had a .276 average, 13 homers and 69 RBI combined while he played with the Astros and Cubs. In 1996, Gonzalez batted .271 with 15 homers and 79 RBI.
Gonzalez signed a one-year deal to return to the Astros in 1997. During 1997, he batted .258 with 10 homers and 68 RBI.
Gonzalez signed a one-year deal for the Tigers in 1998. In 1998, he batted .267 with 23 homers and 71 RBI.
In 1999, Gonzalez was traded to the Diamondbacks for Karim García. Gonzalez began to become a star during his tenure with Arizona. He helped the Diamondbacks into title contention immediately, hitting a career-best .336 in 1999, leading the NL in hits with 206 and helping them win the National League's western division that season before the team fell to the New York Mets in a divisional playoff series. He was selected to his first All-Star Team in 1999. In 2000, the Diamondbacks came in third place in their division. He also blasted 31 home runs and cracked 192 hits.
In 2001, Gonzalez astonished many when he hit 57 home runs, his personal best for one season and almost twice as many as he hit in any other season. The total is the third most in National League history for a left-handed batter (behind Barry Bonds's record 73, which also came in 2001, and Ryan Howard, who hit 58 in 2006). Gonzalez was selected to his second All-Star Team and finished second in the National League in hits with 198. Gonzalez also won the Home Run Derby that year.
The Diamondbacks reached the World Series that year and faced off against the New York Yankees, who featured Gonzalez's childhood friend Tino Martinez starting at 1st base. In the climactic moment, Gonzalez came to the plate in the bottom of the 9th inning of game 7, with the score even at 2-2, the bases loaded and 1 out. The Yankee pitcher was Mariano Rivera, one of the game's most feared closers with an especially good record in the postseason (Rivera had never blown a save chance in a World Series before, or since). Gonzalez swung at Rivera's 0-1 pitch and hit the game-winning bloop single into left field that sealed the first franchise World Series title for Arizona.
He was also selected to All-Star Teams in 2002 and 2003. During the 2002 season, Gonzalez received publicity as a piece of gum chewed by Gonzalez during a spring training game was sold for $10,000 on April 15, 2002. The buyer was Curt Mueller, owner of Mueller Sports Medicine Inc., manufacturer of the gum, Quench.
On May 22, 2004, Gonzalez got his 2,000th career hit in a game against the Florida Marlins, though his season ended early when he had Tommy John surgery in August. In 2005, he was selected to his fifth All-Star Team. On April 18, 2006, he got his 500th career double, becoming the 20th player in Major League history to hit 500 doubles and 300 home runs. On May 13, 2006, he passed Babe Ruth for 38th place all-time for the most doubles hit in league history.
On June 15, 2006, The Arizona Republic printed an interview by columnist E. J. Montini with Diamondback managing general partner Ken Kendrick. In the interview, Kendrick mentioned whispers of alleged steroid use by Gonzalez; in the interview Kendrick never directly accused Gonzalez of using performance-enhancing drugs. The interview came 8 days after Diamondback relief pitcher Jason Grimsley was released by the team after the team learned that federal agents had searched his home looking for evidence that he was a distributor of human growth hormone and other performance-enhancing drugs. On June 16, 2006 an angry Gonzalez called a press conference to deny that he had ever used steroids.
On September 14, 2006, the Diamondbacks announced that they would not pick up the team option of $10 million to re-sign Gonzalez after the 2006 season. On December 7, Gonzalez signed a one-year contract with the Los Angeles Dodgers for $7 million for the 2007 season.
Gonzalez hit his first home run as a Dodger on Sunday, April 8, 2007 versus Barry Zito of the San Francisco Giants. He hit two home runs in that game. In his only season with the Dodgers, he was productive offensively, but struggled defensively. Many times throughout the season, he would be taken out late in the game due to his bad defense. Towards the end of the season, he was benched in favor of Matt Kemp, a top Dodger prospect at the time. He was upset about it and publicly said he was not interested in returning to the Dodgers before the season was even over. He hit .278 with 15 home runs and 68 RBI in 2007.
On February 7, 2008, he signed with the Florida Marlins. The deal was reportedly worth $2 million for 1 season. Gonzalez played in 136 games for the Marlins in 2008, batting .261.
Gonzalez announced his retirement on August 29, 2009 and joined the Diamondbacks front office as a special assistant to the president. In 2010, the Diamondbacks further announced that Gonzalez would be the first Diamondbacks player to have his number, #20, retired on August 7.
With businessman and entrepreneur Anthony Conti, Gonzalez has founded IsTalking, LLC, a Phoenix-based company that develops new social networking Web sites exclusively for college students. The company launched a new social network with Arizona State University called ASUIsTalking.com. He has also formed a partnership with the ASU Alumni Association to be the exclusive online social-network for its 250,000 members.
Gonzalez has served as a color commentator on ESPN Radio's broadcasts of National League Division Series games in recent years, and also worked on Fox Sports' television broadcast of the 2006 National League Championship Series.
Gonzalez formerly owned and operated a restaurant called Gonzo's, located in oldtown/downtown Gilbert, Arizona. It then changed name several times, and as of March, 2007, it is called "The Grain Belt". The restaurant closed in 2009. In 2012, Postinos opened its 3rd Arizona location in its place. Gonzalez is a prominent member of the U.S.Republican Party. As a resident of Arizona, he wrote a letter of endorsement for Arizona's Junior Senator, Jon Kyl, who won his bid for re-election in 2006. He also endorsed Arizona's other Senator, 2008 GOP Presidential Nominee John McCain, over former congressman J.D. Hayworth in 2010. Gonzalez was also the Celebrity face for a cornfield maze in Queen Creek, Arizona for the Schnepf Farms' annual Celebrity Maze. Gonzalez is the first local celebrity featured. Oprah Winfrey, Larry King and Jay Leno were featured in the past.
Gonzalez currently serves as a member of the board of the Baseball Assistance Team, a 501(c)(3) non-profit organization dedicated to helping former Major League, Minor League, and Negro League players through financial and medical hardships.
The Diamondbacks built a Little League ballfield in his honor at Tempe Beach Park in Tempe, Arizona.
Gonzalez was inducted into the Hispanic Heritage Baseball Museum Hall of Fame on July 9, 2011 at the MLB All-Star Fan Fest in Phoenix.
Gonzalez and his family (which includes wife Christine and triplets Megan, Jacob and Alyssa) are residents of Scottsdale, Arizona. Jacob was selected by the San Francisco Giants in the 2017 MLB draft.