[5] Mauer attended the same high school as Baseball Hall of Famer and former Milwaukee Brewer Paul Molitor who later became his major league manager with the Twins.

"[9] A stand-out in baseball, Mauer struck out only once during his four-year high school career (though he did strike out in the All-Star game his senior year which isn’t included in his overall stats).

[9] He also set a Minnesota high school record and tied the national preps mark by hitting a home run in seven consecutive games.

[12] After committing to play football at Florida State University, Mauer ultimately decided instead to enter the Major League Baseball Draft.

[12] Mauer was selected by the Twins as the first overall pick of the 2001 draft, ahead of college pitcher Mark Prior, who was taken second overall by the Chicago Cubs.

In 2005, Mauer returned to the Twins' lineup for his first full major league season, and batted .294 with 144 hits, nine home runs and 55 RBI in 131 games.

[25] Mauer finished the 2006 regular season with a .347 batting average, edging the New York Yankees' Derek Jeter and Robinson Canó 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 the Major Leagues, a feat not achieved by the previous three catchers to win NL batting titles.

[31] He finished fourth in the balloting for American League Most Valuable Player, behind Dustin Pedroia, Justin Morneau, and Kevin Youkilis.

He was unable to take part in team workouts during spring training due to the pain in his lower back, which he first began experiencing late in the 2008 season.

[41] He was selected to the 2009 MLB All-Star Game as the starting catcher and participated in the Home Run Derby, losing a tiebreaker to Albert Pujols in the first round.

[26] At the time, he had won as many batting championships in a span of four years as all other Major League catchers in the history of baseball combined.

[18] Facing the Yankees in the ALDS, Mauer continued to swing the bat well, recording five hits in 12 at-bats plus two walks, but the Twins were swept by the eventual World Series champions in three games.

[45] On November 23, Mauer was named the 2009 American League Most Valuable Player by the Baseball Writers' Association of America over Yankees teammates Mark Teixeira and Derek Jeter, earning 27 of the 28 first-place votes.

[18] On March 21, 2010, Mauer agreed to an eight-year contract extension with the Twins worth $184 million which took effect in the 2011 and ran through the 2018 season.

[51] Mauer underwent arthroscopic knee surgery after the 2010 season, and missed most of spring training due to a difficult recovery from the operation.

[53] Team doctors believed his problem, termed a "bilateral leg weakness", was due to too light a workload during spring training.

[52] The following week, he went on a further rehabilitation assignment to the Twins' Class A affiliate, the Fort Myers Miracle, a team managed by his older brother Jake.

[57] Mauer made his first Major League start at first base on July 7, 2011, in Chicago, where he turned the first ball hit to him into an unassisted double play.

[63] On August 27, Mauer played his 832nd game at catcher for the Twins, breaking a franchise record set by Earl Battey.

[68] After the 2013 season, the Twins announced that Mauer would permanently move to first base in order to protect their star player from further concussions and the day-to-day physical wear of being a major league catcher.

[18] On April 12, 2018, Mauer became the 287th player in the history of Major League Baseball to collect 2,000 hits with a two-run seventh inning single off White Sox pitcher Aaron Bummer.

[71] In the ninth inning of the last game of the 2018 MLB season on September 30, 2018, at Target Field, amidst speculation that he would retire at the end of the year, Mauer made an appearance as catcher for the first time since his concussion in 2013, before being removed for backup Chris Gimenez after one pitch.

Mauer modeled for Perry Ellis in the 2004–05 off-season, and is featured in television commercials for Head & Shoulders, Pepsi, ESPN, Fox Sports Net, PlayStation 3, Gatorade and my29.

Mauer taped an episode of Homecoming with Rick Reilly for ESPN on January 27, 2010, at Cretin-Derham Hall High School, his alma mater, in St. Paul, Minnesota.

[94] On December 11, 2011, Mauer announced his engagement to Saint Paul nurse Maddie Bisanz, his girlfriend of about 18 months and a fellow graduate of Cretin-Derham Hall High School.

Some observers concluded that this was an attempt to induce Joe to sign a contract, but Mike Radcliff, the scouting director of the Twins, denied this.

[103] Jake Mauer ended his playing career after the 2005 season but went on to manage the Gulf Coast League Twins (Rookie-level).

After winning the GCL South with the Twins in 2009, Jake moved up to the High-A Fort Myers Miracle and managed the team for two seasons.

[104] Mauer's other brother, Billy, signed with the Twins as an undrafted free agent in 2003 and pitched in the organization for three seasons before chronic shoulder problems forced him to retire from the game.