Witt spent parts of five seasons in Major League Baseball (MLB), appearing with the Toronto Blue Jays, San Diego Padres, Detroit Tigers and Tampa Bay Devil Rays, most often as a designated hitter.

He also played parts of two seasons in Nippon Professional Baseball (NPB), spending time with the Yokohama BayStars and Tohoku Rakuten Golden Eagles.

He made his major league debut with the Blue Jays as a September call-up in 1998, collecting one hit in seven at-bats.

On October 6, 2001, Witt pinch-ran for Tony Gwynn, who had recorded his final Major League hit with a double.

He spent the entire season in the minors with the Louisville Bats(AAA), then was granted free agency on October 15, 2002.

He returned to North America the next season, and earned International League Most Valuable Player honors after leading all of minor league baseball with 36 home runs, while setting a Triple-A Durham Bulls franchise record and a Rays' organization record.

Witt and his wife Lori (née Long) live in Texas and have four sons: Tanner, Preston, Cullen and Ripken, and a daughter, Skyler.