Ex-MLB player Jeremy Giambi -- who played in the MLB from 1998 to 2003 -- has passed away, TMZ Sports has learned. He was 47 years old.
Giambi played for the Royals, Athletics, Phillies, and Red Sox over the course of his career ... earning a .263 batting average and hitting 52 home runs and 209 runs batted in.
His best season came in 2001, when he played in 124 games and had 12 homers.
Jeremy is the brother of Jason -- the American League MVP in 2000, who played for the Athletics, Yankees, Rockies and Indians.