Zimmer's son, Tom, said his father died peacefully. He had been hospitalized since April 16 after having heart surgery.
He played 12 seasons and more than 1,000 games in the big leagues, including Opening Day 1962 with the Mets, who took him from the Cubs in the expansion draft before that season. The next month, the Mets traded him to the Reds for pitcher Bob Miller and infielder Cliff Cook.
"We are saddened by the passing of Don Zimmer, an original Met, who played in our very first game," the Mets said. "He gave six decades of his life to baseball. Our thoughts and prayers are with his family.”