In a video posted on The Players' Tribune website on the same day he celebrated his 40th birthday, Ortiz said he felt it was time to experience the next chapter of his life.
"I would like people to remember me as a guy that was just part of the family, you know, a guy that was trying to do the best, not just on the field but with everyone around him," Ortiz said. "Baseball is not just based on putting up numbers. This is our second family. Whoever is around you on a daily basis is like a second family, and I always had good thoughts for everyone around me. Baseball, besides God, it just helped flip my whole life over, not just mine, my whole family, you know what I'm saying, because I see how people struggle out there. I struggled before and I know how hard it is to make it to the top. It's something you've got to thank God every day for."
Ortiz's plans were first reported by Fox Sports on Tuesday.
Ortiz, a nine-time All-Star and a six-time Silver Slugger Award winner, finished last season with a .273 average, 108 RBIs and 37 home runs -- his most for a season since 2006, when he set the team record with 54 homers.
He has hit 503 homers in his career, including 445 during his 13 seasons with the Red Sox, the third-most in franchise history behind Ted Williams (521) and Carl Yastrzemski (452). He ranks 27th on the all-time home run list, just one away from tying Hall of Famer Eddie Murray.
Only 10 position players in Red Sox history have played past their 40th birthday, and only three have played in as many as 100 games past that age: Yastrzemski, who played 446 games; Williams, 216; and Bing Miller, 109.
"I'm really proud of what I had accomplished through the years," Ortiz said. "I'm very thankful for having fans like you guys who have supported me through my career. I wish I could play another 40 years to have you guys behind me, but it doesn't work that way."
Primarily a designated hitter in his career, the debate going forward will be whether Ortiz's numbers are worthy of Cooperstown. He has the most career home runs as a DH with 447 -- well ahead of Hall of Famer Frank Thomas (269), who ranks second on that list, according to Elias Sports Bureau.
His ranking in Red Sox lore, meanwhile, never will be questioned.
After playing six semi-productive seasons with the Twins, who released him after the 2002 season, Ortiz came to Boston as an unheralded platoon first baseman, found a spot at designated hitter and emerged as one of the best sluggers in baseball history.
Affectionately known as "Big Papi," Ortiz led the Red Sox to three World Series championships in 2004, '07 and '13. He has starred in October, owning the best World Series batting average (.455), on-base percentage (.576) and slugging percentage (.795) for players in the Fall Classic (minimum 50 plate appearances). He was named MVP of the 2013 World Series.
"It is difficult to adequately convey what David Ortiz has meant to the Boston Red Sox," owner John Henry said in a statement. "For his teammates, he has been the one constant force underpinning what it means to play for this organization and making it fun. For the fans, he has been the one consistent force behind three world championships, lifting all of us on his broad shoulders exactly when we needed it. For the community, he has been the hero providing leadership off the field in ways that consistently make a difference often completely unseen. And for those of us who have had the honor of knowing him all these years, he has been exactly what you hope to see in a man who has been the face of this organization.
"As he concludes his illustrious career in this, his final season, we look forward to joining everyone in the game of baseball in showing him just how much Big Papi has meant to all of us."
Another New England great, Patriots quarterback Tom Brady, said Ortiz will be missed.
"He's given all of our fans so much reason to cheer," Brady said. "He's been an incredible player. It'll be sad to see him go. I've got a lot of respect for him and the way that he's always brought a great leadership to his team. He's been a great example."
The Red Sox will be looking to rebound in 2016 after finishing last in the American League East with a 78-84 record this past season.
"After next year, time is up. So let's enjoy next season," Ortiz said.
Information from The Associated Press was used in this report.