Sandoval's release marks the second time in the 2020 season that San Francisco has parted ways with a fan favorite. The Giants also released struggling outfielder Hunter Pence in August after designating him for assignment.
Sandoval -- nicknamed "Kung Fu Panda" -- was in his second stint with the Giants. The 34-year-old slugger was hitting .220 with one home run and six RBIs this season.
In an Instagram post Thursday, Sandoval expressed his appreciation to the Giants organization.
"It's been an honor and privilege to play for you," Sandoval wrote. "My heart will forever be in San Francisco."
Sandoval rejoined the Giants in 2017 after his release from the Boston Red Sox. The Red Sox cut him only three seasons into a five-year, $95 million contract he signed with the club after the 2014 campaign.
In 1,310 career games, Sandoval has recorded a .279 batting average with 149 home runs and 628 RBIs. He was an All-Star selection in 2011-12 and was the World Series MVP in 2012.