A captain on the Patriots' Super Bowl championship team in 2014, Connolly relayed his decision in an interview with ESPN.com.
When asked if winning the Super Bowl was a catalyst to retire, Connolly said: "It definitely played a part in it; helped me sleep better. I'm more at ease with the decision."
Connolly, 32, felt he could have played another one or two seasons. He had interest from NFL clubs, but was weighing multiple factors.
He and his wife, Lori, have three daughters under 6 years old, and he didn't want to move the family or be away from them while he played in a different city.
Furthermore, health was the "biggest factor" in his thought process, as he had four diagnosed concussions in the NFL, as well as a fifth when playing at Marquette High School in Chesterfield, Missouri.
"It's important to me to leave the game healthy," Connolly said. "I'm able to be here for my kids and walk away on my own terms. I feel like I got everything I could out of football in playing 10 years, winning a Super Bowl, and playing alongside some truly great players."
The Patriots were a major part of that, as Connolly was signed to the practice squad in 2007 and he's been with the franchise since. He initially entered the NFL as an undrafted free agent with the Jacksonville Jaguars in 2005 out of Southeast Missouri State and appeared in 89 regular-season games, with 71 starts, in his career. In addition, Connolly started in 11 playoff games (including two Super Bowls).
His most notable play was a 71-yard kickoff return in a game against Green Bay during the 2010 season, when he fielded a bouncing ball as part of the wedge and surprisingly had room to rumble down the field.
The 6-foot-4, 305-pound Connolly played left guard, center and right guard at various points in his time with the Patriots, and was noted by longtime assistant coach Dante Scarnecchia for having exemplary athleticism. His move to left guard last season was one main reason for the line's dramatic improvement in play.
A first-time team captain in 2014, he was a stabilizing presence, tapped to help fill the void left by the trade of franchise linchpin Logan Mankins to Tampa Bay in August.
Connolly, who turns 33 on Sept. 2, was courted by Tampa Bay this offseason and took a free-agent visit there.
Connolly added that he was going back and forth on his retirement decision until about a month or two ago. Specifically, he was thinking about his four documented concussions, the most recent in the 2014 season, and came to the decision to retire after speaking with his wife and doctors.
Connolly doesn't have immediate plans in retirement, with a focus of spending time with his daughters because when playing "there's a lot of time lost with family."
As for personal enjoyment, he attended Wednesday's ESPYS. Many of his friends already are aware of his retirement decision, and the Patriots are as well.
"The locker room friendships, I just don't know if you can get that type of connection in any job in the world; being together in training camp and hotels on the road, that close-knit bond is something I'll definitely miss," Connolly said.
"With my football career coming to a close I am grateful for the opportunity given to me by the Kraft family and Coach [Bill] Belichick. It is an honor to have been part of such a great organization for the past eight seasons."