1987 Seattle Mariners season

The Seattle Mariners 1987 season was their 11th since the franchise creation, and ended the season finishing fourth in the American League West with a record of .480.

Offseason

 * December 5, 1986: The Mariners traded a player to be named later to the Pittsburgh Pirates for Rick Rentería. The Mariners completed the deal by sending Bob Siegel (minors) to the Pirates on December 10.
 * December 10, 1986: Danny Tartabull and Rick Luecken were traded by the Mariners to the Kansas City Royals for Scott Bankhead, Steve Shields, and Mike Kingery.
 * December 17, 1986: Ricky Nelson was traded by the Mariners to the New York Mets for Doug Gwosdz.
 * March 31, 1987: Pete Ladd was released by the Mariners.

Notable transactions

 * May 12, 1987: Mark Huismann was traded by the Mariners to the Cleveland Indians for Dave Gallagher.
 * June 2, 1987: 1987 Major League Baseball Draft
 * Ken Griffey Jr. was drafted by the Seattle Mariners in the 1st round (1st pick).
 * Pat Listach was drafted by the Mariners in the 23rd round, but did not sign.

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''

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

Awards and honors

 * Mark Langston – American League Leader, Strikeouts (262)

All-Star Game