Bloomquist was All-State and all-league MVP in baseball at South Kitsap High School in Port Orchard, Washington and was an eighth round pick in 1996 MLB draft. He was a high school teammate with former MLB player Jason Ellison. He also played quarterback for South Kitsap. In his junior season, the team won the state AAA football championship

He chose to accept a scholarship to Arizona State University. In 1998, Bloomquist tied a College World Series single-game record with five hits in a game with Long Beach State. He was honored as Pac-10 Player of the Year in 1999 and was named first-team All-American by Baseball America. He finished his college career with a .394 (256/649) average over three seasons and was named ASU On Deck Circle Most Valuable Player.

The Mariners signed Bloomquist to a contract extension through the 2008 season worth $1,875,000, in 2006. On June 15, 2007, he hit an inside-the-park home run in Minute Maid Park. On June 26, 2007, Bloomquist hit a lead-off home run in the second inning—on what was his 1,000th career at-bat.

On January 9, 2009, Bloomquist signed a two-year deal with the Kansas City Royals. He played in 197 games with the Royals over parts of 2 seasons, hitting .265.

On September 13, 2010, Bloomquist was traded to the Cincinnati Reds for a player to be named later, or cash. In 11 games with the Reds, he hit .333.

On January 18, 2011, Bloomquist signed a one-year contract with the Arizona Diamondbacks. He hit .266 in 97 games with the Diamondbacks in 2011 and re-signed with the team after the season.

On December 5, 2013, Bloomquist signed a two-year deal to return to the Seattle Mariners. On July 2, 2015, Bloomquist was designated for assignment, and shortstop Chris Taylor called up from the Triple-A Tacoma Rainiers to take his roster spot.

On March 11, 2016, Bloomquist announced his retirement on Twitter.