The 1986 American League Championship Series was a best-of-seven Major League Baseball postseason series between the Boston Red Sox and the California Angels for the right to advance to the 1986 World Series to face the winner of the 1986 National League Championship Series. The Red Sox came in with a 95–66 record and the AL East division title, while the Angels went 92–70 during the regular season to win the AL West.

The American League Championship Series (ALCS), also known as the American League Pennant, is a best-of-seven playoff and one of two League Championship Series comprising the penultimate round of Major League Baseball's (MLB) postseason. The winner of the ALCS wins the AL pennant and advances to the World Series, MLB's championship series, to play the winner of the National League's (NL) Championship Series. The ALCS began in 1969 as a best-of-five playoff and used this format until 1985, when it changed to its current best-of-seven format.