Born in St. Paul, Minnesota, Mauer was a three-sport athlete, baseball, football, and basketball, for St. Paul's Cretin-Derham Hall Raiders. He was even good enough to make it into a Sports Illustrated issue as a "Face In The Crowd". A stand-out in baseball, Mauer was struck out only once during his high school career, while hitting .605 during his senior season. He also set a Minnesota high school record by homering in seven consecutive games. Mauer caught for the Team USA Junior National team from 1998 to 2000 and hit .522 during his final year on the team. He was voted best hitter at the world tournament in Panama in 2000. In 2001, Mauer was voted the Minnesota District V Player of the Year.

During his senior season as the Raiders' quarterback, Mauer completed 178 of 288 passes for 3,022 yards and 41 touchdowns with only two interceptions and finished his two-year career as a starter with 5,528 yards and 73 touchdowns. He led the Raiders to two consecutive Class 5A state championship game appearances, winning the title in 1999, and once threw seven touchdown passes in a single playoff game. Mauer was named Gatorade's National Player of the Year, Parade and USA Today Player of the Year and a Reebok/ESPN High School All-American. Mauer was also named "National High School Quarterback Of The Year" in 2000 by The National Quarterback Club. He was also named to the All-State team during his final two years on Cretin-Derham's basketball team. However, he turned down a football scholarship from Florida State University to enter the Major League Baseball Draft. Mauer was selected by the Twins as the first overall pick of the 2001 draft, ahead of another elite prospect, Mark Prior, who was taken second overall in the Major League Baseball Draft by the Chicago Cubs.

Mauer was part of the United States' roster at the 2003 All-Star Futures Game at US Cellular Field before being promoted to the Twins' roster in 2004 after his predecessor, A.J. Pierzynski, was traded to the San Francisco Giants in the 2003 off-season. Mauer went 2 for 3 in his Major League debut, hitting a single off Rafael Betancourt of the Cleveland Indians for his first major-league hit.

A knee injury to his left medial meniscus on April 7, 2004 required surgery and sidelined Mauer for over a month. After a rehabilitation stint with the Twins' AAA affiliate Rochester Red Wings, Mauer returned to the Twins' lineup in June. In July, pain and swelling in his knee forced an early end to Mauer's 2004 season.

Following his injury-shortened 2004, Mauer signed a contract worth $5.7 million with the Twins on January 24, 2005. In 2005, Mauer returned to the Twins' lineup for his first full major league season and had 144 hits in 131 games, ending the year with an average of .294.

In 2006, Mauer's performance throughout the months of May and June gathered attention from the national media. He recorded a .528 average over the first ten days of June and hit .452 over the course of the month. He was also the first player since Mike Piazza in 1997 to reach base four or more times for five consecutive games. On June 12, Mauer was named the American League Player of the Week by Major League Baseball for his performance the week of June 4-11, during which he hit .625 (15-for-24) with 5 doubles, 4 RBI and 2 stolen bases. He was also named Player of the Month for June after batting .452 with a .624 slugging percentage and .528 on base percentage, 11 doubles, 14 RBI and 18 runs. Along with Johan Santana (Pitcher of the Month) and Francisco Liriano (Rookie of the Month), Mauer was part of the first-ever single-team sweep of MLB's three monthly awards.[11] On July 2, Mauer was selected by the players to his first All-Star Game.

Mauer finished the 2006 regular season with a .347 batting average, edging the Yankees' Derek Jeter and Robinson Cano to win the American League batting title and become the first-ever American League catcher to win the crown and the first catcher to claim the title since Ernie Lombardi in 1942 with the Boston Braves. His .347 average was the highest in either league, a feat not achieved by the previous three catchers to win NL batting titles. He was the youngest to win a batting title since Alex Rodriguez in 1996.

After going 2-for-4 in the last game of the 2006 regular season, Mauer confessed to reporters, "When I told you I wasn’t thinking about the batting title? I was lying. I’ve never been that nervous in my life. I haven’t felt anything like that since Opening Day as a rookie.”

Mauer won his first Silver Slugger award in 2006, announced on November 10, 2006, along with teammate Justin Morneau, who also won a Silver Slugger award that year.

On February 11, 2007, Mauer agreed to a four-year, $33 million contract with the Twins to avoid arbitration. The deal ensures that Mauer will remain in Minnesota long enough to play in the Twins' new outdoor stadium in 2010.

--Wikipedia