He played in Major League Baseball (MLB) for the Arizona Diamondbacks, Toronto Blue Jays, Pittsburgh Pirates, Atlanta Braves, New York Yankees, and Milwaukee Brewers from 2001 through 2014.

[3] He was also part of the Diamondbacks' postseason roster to serve as a backup first baseman and eventually won the World Series over the Yankees.

[3] On July 23, he had a career high 6 RBI against the Cincinnati Reds, hitting two home runs, including a grand slam.

Fans would raise their hands over their heads in an "O" symbol – some brought cardboard cut outs of the letter "O" – and would chant a prolonged "O" sound to honor Overbay.

"[7] On December 7, 2005, Overbay was traded from the Brewers along with pitching prospect Ty Taubenheim to the Toronto Blue Jays in exchange for outfielder Gabe Gross and pitchers Dave Bush and Zach Jackson.

[8] Although the trade was acknowledged as a needed acquisition for the Blue Jays,[9] Overbay did not have the statistical impact hoped for, at least beyond 2006.

[13] On June 4, 2007, Overbay was hit by a pitch in the sixth inning of a game against the Chicago White Sox.

The pitch was a high and inside fastball that ran in and hit him in the hand, resulting in a fracture that was estimated to sideline him for four to six weeks.

Overbay set a new team record on May 25, 2008, by reaching base in his 12th consecutive plate appearance after walking on a full count in the second inning.

[16] Overbay is also one of only 15 players to hit into an unassisted triple play, serving up Asdrúbal Cabrera of the Cleveland Indians on May 12, 2008.

[29] He was released by the Red Sox on March 26, 2013, and signed by the New York Yankees to a minor league deal later that day.

[34] On June 26, the Yankees announced that Mark Teixeira was going to undergo season-ending wrist surgery, allowing Overbay to be the everyday first baseman for the remainder of the season.

On January 20, 2014, Overbay agreed to a minor league contract with the Milwaukee Brewers that contained an invite to spring training.

Manager Ron Roenicke cited Overbay's good defense skills at first base and his veteran status in making his decision.

He faced only one batter (Ryan Doumit), getting the needed out on a popup to the shortstop Jean Segura.