The 2006 American League Division Series (ALDS), the opening round of the 2006 American League playoffs, began on Tuesday, October 3, and ended on Saturday, October 7, with the champions of the three AL divisions—along with a "wild card" team—participating in two best-of-five series. They were:

The higher seed (in parentheses) had the home field advantage, which was determined by playing record.

The Athletics and Tigers met in the AL Championship Series, where a Detroit sweep made the Tigers the American League champions. The Tigers then faced the St. Louis Cardinals in the 2006 World Series, and lost, four games to one.

The AL playoff race of 2006 was unusually dramatic, with the last divisional championship and the wild card berth undecided until the final day of the season, and the most unlikely of all of the AL's playoff contenders taking the top spot in the AL Central and the second seed.

In the AL East, the New York Yankees (97–65) clinched the division when the Boston Red Sox were eliminated from the playoffs by the Minnesota Twins (96–66) on September 20. The Oakland Athletics (92–69) clinched the AL West on September 26, and in the AL Central, the Twins won the division by a single game over the Wild Card Detroit Tigers (95–67) after Detroit—who had led the division for the entire season—lost their last five games. Minnesota had set a torrid pace since June 7, after a horrible start. The Twins sewed up their playoff berth with an 8–1 win over the Kansas City Royals. They clinched the Central Division title, their fourth in five years, with a 5–1 victory and a 10–8 Detroit loss to the Royals on the last day of the season. The Twins' 96–66 mark is their best since the 98–64 AL West Champion Twins of 1970.

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