Carter passed at 4:10 p.m. ET, according to an entry on his family's online journal.
"He is in heaven and has reunited with his mom and dad," Carter's daughter, Kimmy Bloemers, wrote on the journal. "I believe with all my heart that Dad had a STANDING OVATION as he walked through the gates of heaven to be with Jesus."
Carter hit 324 home runs over a 19-year run with the Expos, Mets, Giants and Dodgers, finishing his career back where he started, in Montreal in 1992. He entered the Hall of Fame in 2003 with an Expos cap, on a plaque referring to his "signature smile" and clutch hitting.
"Driven by a remarkable enthusiasm for the game, Gary Carter became one of the elite catchers of all-time," said Commissioner Allan H. (Bud) Selig. "'The Kid' was an 11-time All-Star and a durable, consistent slugger for the Montreal Expos and the New York Mets, and he ranks among the most beloved players in the history of both of those franchises. Like all baseball fans, I will always remember his leadership for the '86 Mets and his pivotal role in one of the greatest World Series ever played.
"On behalf of Major League Baseball, I extend my deepest condolences to Gary's wife, Sandy; their daughters, Christy and Kimmie; their son, D.J.; their grandchildren; his friends and his many fans."Carter hit 24 homers and knocked in 105 runs for the 1986 Mets, earning one of his 11 career All-Star selections and finishing third in National League Most Valuable Player Award voting. Carter's leap into the arms of reliever Jesse Orosco after the final out of Game 7 of the World Series remains one of the most indelible images in Mets history.
A three-time Gold Glove winner and two-time All-Star Game MVP, Carter was inducted into the Mets Hall of Fame and Canadian Baseball Hall of Fame in 2001. His uniform No. 8 was retired by the Expos in '03. He caught the fourth-most games (2,056) in Major League history and, when not catching, played as an outfielder and first baseman.
Mets chairman and CEO Fred Wilpon, president Saul Katz and COO Jeff Wilpon released the following statement upon Carter's passing:
"On behalf of everyone at the Mets, we extend our deepest and heartfelt condolences to Gary's family. ... His nickname, 'The Kid,' captured how Gary approached life. He did everything with enthusiasm and with gusto, on and off the field. His smile was infectious. He guided our young pitching staff to the World Series title in 1986 and he devoted an equal amount of time and energy raising awareness for a multitude of charities and community causes. He was a Hall of Famer in everything he did."
Carter's manager in New York, Davey Johnson, recalled the written reports his catcher kept on all National League hitters, dubbing him "a one-man scouting system." The general manager who acquired him, Frank Cashen, called Carter "the perfect guy for so many reasons."
"He was the idea catcher for our young pitching staff," Johnson said.
Carter, who spent time managing two of New York's Class A Minor League affiliates last decade and was named Gulf Coast League Manger of the Year in 2005, most recently served as the head baseball coach at Palm Beach Atlantic University in Florida. Prior to his illness, Carter had been outspoken in his desire to one day manage the Mets.
"The baseball community has lost a Hall of Fame player and a Hall of Fame person," former teammate and current Mets third-base coach Tim Teufel said in a statement. "He was a good man and will be missed terribly."
"What he added to the team was character," another teammate, Darryl Strawberry, said. "His approach to the game was contagious. It spread to the rest of us. He helped each of us understand what it took to win."
Carter made his last public appearance at Palm Beach Atlantic's home opener on Feb. 2, 18 days after making a brief speech at his own charity golf tournament dinner on Jan. 15.
"My prayers go out to his family," former teammate Mookie Wilson said in a telephone interview Thursday evening. "Even though we knew he was dealing with the cancer ... it's a little shock to me right now."
The New York chapter of the Baseball Writers' Association of America honored Carter in January with its Milton Richman/Dan Castellano "You Gotta Have Heart" award.
"When you think of the great baseball field generals, you think Gary Carter," National Baseball Hall of Fame president Jeff Idelson said in a statement. "He ran the game from behind the plate with strong leadership and passion. The Kid's contribution to our National Pastime is big, but his heart was even bigger. We'll always remember his caring way, ever-present smile and strong devotion to family, community and the Baseball Hall of Fame."
The Hall of Fame plans to announce funeral arrangements when they become available.