Outfielder Justin Upton and DH Nelson Cruz rounded out the American League winners.
The Silver Slugger is awarded to the best offensive player at each position, in each league, as voted by managers and coaches. His extra-base hits and doubles totals ranked in the top five in a single-season in franchise history.
2017 had the most home runs in a single season, with the 2000 record being broken on September 19.
World Series champions Jose Altuve and George Springer were among the 2017 Louisville Slugger Silver Slugger Award winners announced Thursday.
Trout missed about six weeks with a thumb injury, but still finished the season hitting.306 with 33 homers and a league-leading 1.071 OPS. For the regular season, the second baseman posted a.346 batting average and led the AL in hits with 204, becoming the first player in MLB history to be the outright leader in hits in his league in four consecutive seasons.
Cruz led the Mariners in games, runs, home runs, RBIs, walks, on-base percentage, slugging, OPS and extra-base hits.
Two members of the Cleveland Indians were among eight 2017 Silver Slugger Award recipients.
Bob Forsch (1980, 1987) and Jason Marquis (2005) are the only previous Cardinals pitchers to win a Silver Slugger Award.
It was the first Silver Slugger for each player.
Posey hit.320 with a.400 on-base percentage and.462 slugging percentage.