McCovey had been battling multiple health issues and he reportedly passed away peacefully at Stanford Hospital on Wednesday (October 31). McCovey, who almost died from an infection four years ago, was fighting another one that sent him to the hospital last week.
"San Francisco and the entire baseball community lost a true gentleman and legend, and our collective hearts are broken", Giants president and chief executive officer Laurence M. Baer said in a statement. He had attended games at AT&T Park as recently as the final game of the 2018 season.
McCovey was elected to the Baseball Hall of Fame on the first ballot in 1986.
Nicknamed "Stretch", the 6-foot-4-inch McCovey, along with teammate Willie Mays, terrorized pitchers during the 13 seasons they played together on the Giants.
"I am grateful that my father passed peacefully surrounded by his family and friends while listening to his favorite sports channel", said Willie's daughter Allison McCovey.
McCovey, a six-time All-Star who also played for the San Diego Padres and Oakland Athletics, finished his career with 521 home runs, the same number as another great left-handed hitter: Ted Williams. In 1980, the Giants established the "Willie Mac" Award, an honor bestowed on the player who "best exemplifies the spirit and leadership" shown by McCovey.
"Every moment he will be terribly missed", said McCovey's wife, Estella, whom he married this past summer. 'He was my best friend and husband. The SF Gate profile quotes him saying (about his relationship with Estela): "We got lots of plans to do, so I've got to get well... Living life without him will never be the same".
McCovey settled into his role over the next three years, helping the Giants win the NL pennant in 1962 by hitting 20 home runs in just 91 games.
San Francisco Giants Willie McCovey (4) portrait from his 1964 season with the San Francisco Giants. McCovey also is survived by sister Frances and brothers Clauzell and Cleon. "When you think of McCovey, you think of power", he said, adding that some people forget how great of an all around player he was. "This is two in three years".
McCovey presented the "Willie Mac Award" each season - except in 2014 while dealing with complications from the infection - an honor voted on by the players, coaches and training staff to recognize the team's player most exhibiting McCovey's inspirational example both on the field and in the clubhouse.
The Giants said a public celebration of McCovey's life would be held at a later date.