The Seattle Mariners 1997 season was their 21st season, and the team won their second American League West title, with a record of .550, six games ahead of the runner-up Anaheim Angels. For the second straight year, they led the AL in runs scored (925) and shattered the all-time record for most home runs hit by a team in one season (set at 257 by the Baltimore Orioles the year before) with 264. Five Mariners scored at least 100 runs and six hit at least 20 home runs. In addition, the Seattle pitching staff led the league with 1,207 strikeouts. In the postseason, the Mariners lost the ALDS to the Baltimore Orioles in 4 games. The Mariners drew over three million in home attendance for the first time in franchise history, in the penultimate full season at the Kingdome. Ken Griffey Jr. hit a franchise record 56 home runs and won the Most Valuable Player award in the American League. This would be Randy Johnson's final full year in a Mariners uniform, he would be traded to Houston midway through the 1998 season.

Offseason

Regular season

In 1997, Randy Johnson set an American League record for left-handers by striking out 19 batters in a 4–1 loss to the Oakland A's on June 24. On August 8 he matched the feat by setting down 19 Chicago White Sox. Johnson posted a 20–4 record with 291 strikeouts and an ERA of 2.28. He finished second in the Cy Young balloting to Toronto's Roger Clemens.

Opening Day starters

Season standings

Record vs. opponents

Notable transactions

Roster

Player stats

Batting

Starters by position

''Note: Pos = Position; G = Games played; AB = At bats; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in''

Other batters

''Note: G = Games played; AB = At bats; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in''

Pitching

Starting pitchers

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts

Other pitchers

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts

Relief pitchers

Note: G = Games pitched; W = Wins; L = Losses; SV = Saves; ERA = Earned run average; SO = Strikeouts

ALDS

Game 1

October 1, Kingdome

Game 2

October 2, Kingdome

Game 3

October 4, Oriole Park at Camden Yards

Game 4

October 5, Oriole Park at Camden Yards

Awards and honors

Farm system