The presentation happened 16 days after Smoltz and his Atlanta teammates were eliminated by the Houston Astros in an 18-inning National League Division Series game that was the longest in postseason history.
"Truly a little bit of irony here, coming back to this stadium," Smoltz said. "I'd seen enough in 18 innings, but this is the greatest trip of my life."
Commissioner Bud Selig and Roberto Clemente Jr. joined Smoltz at the podium to present this award, which has been given annually since 1971. In 1973, the award was named in honor of the legendary Hall of Famer, who died in a plane crash on Dec. 31, 1972, while on a humanitarian mission to assist earthquake victims in Nicaragua.
Smoltz and his wife, Dyan, who joined him for the ceremony, formed the John and Dyan Smoltz Foundation in 1997 to support their many philanthropic endeavors, including the Kings Ridge Christian School in the Atlanta area. Established in 2001, Kings Ridge has received more than $1 million from the foundation, and Smoltz, a co-founder of the school, has raised nearly $4 million personally.
Smoltz's earliest community endeavors date back to 1992, when he began associating himself with the Atlanta Food Bank and Children's Healthcare of Atlanta. With the Food Bank, he has helped raise money through golf tournaments and silent auctions.
He also continues to support them with his "Strike Out Hunger" program. With every strikeout he records, he donates $100. During his days as a closer, Smoltz renamed the program "Close Out Hunger." With every save, he made a donation.
In addition, twice a year, he signs autographs for fans who donate $20 or bring 20 canned goods to select Braves games. Since beginning these programs in 1997, he's raised over $300,000 and 70,000 pounds of food.
With Children's Healthcare, Smoltz has hosted a celebrity-amateur golf tournament. The tournament has raised more than $1 million over the past 13 years. There are many days in which he will simply stop by hospitals and spend time with sick children. He said his favorite such experiences come when there aren't any television cameras or media members detailing his visit, and his peers have recognized him in the past with the Marvin Miller Man of the Year Award in 2002 and '03.
Tuesday's recognition, Smoltz said, is the pinnacle of his baseball career from an individual standpoint. He also was accompanied by his father, John, who flew in from Michigan. Smoltz's brother was there as well. All of them would have loved to have seen Smoltz on the mound for a sixth World Series and first in this decade (he appeared in 1991, '92, '95, '96 and '99), but this moment may have exceeded any of those indelible memories in the grand scheme of things.
"I can't thank the Roberto Clemente family enough," Smoltz said, calling the late Hall of Famer and award namesake an "icon." "As players, you all know who Roberto Clemente is and what he did and how he did it. But truly I've gotten a chance to achieve some incredible successes. The  Cy Young Award, a  World Series championship, and I'm not saying this because you're here or I'm not saying this because the Commissioner is here, this truly is the greatest award ... that a player can achieve and accomplish. And I mean that. It goes above those awards because it has the opportunity to affect so many people.
"This is who I am, this is how I was raised by my Dad. My wife has given me the amount of time and sacrifice with our four children, and I truly can say when I received this news that it was the greatest time in my 18-year career so far."
Roberto Clemente's widow, Vera, was unable to attend but said, "My congratulations to John Smoltz on his selection. ... His performance on the field and dedication and commitment to the community truly embody the spirit of this award."
Roberto Jr. told Smoltz at the head table: "It's not about being a great player, because everyone knows that already, but this honor is for you as a family, as a person, a special person. And for us, it's a great honor to be very happy that you are the recipient of this award ... and we thank you from the bottom of our hearts for being that special person."
Responding to those comments, Smoltz said, "I thank you for modeling what your Dad had incredibly endowed in baseball. And like you said, everyone knew how great a baseball player he was. But everybody gets to see with each recipient. I feel like of the 700 and some baseball players, to be the one chosen to represent that, I will do, in the times that I feel like it gets very difficult, this will remind me what an incredible award it is.
"And I thank everybody who had a part in it. Commissioner, thank you for baseball, and John Hancock [the award's sponsor] for representing us. I hope to carry on the legacy in the honor of your father. I thank you very, very much."
Every Major League team selected a Roberto Clemente Award recipient who was then eligible for the national award, and those 30 nominees were announced by Major League Baseball on Sept. 7 as part of Roberto Clemente Day in baseball. A panel of dignitaries including Selig and Vera Clemente then selected the award winner.
"I want to say when I reviewed the voting and the 30 people who won for their individual clubs, I mean it really makes you proud to be the commissioner," Selig said. "The qualifications of the other 29 were just remarkable, but John, I have to say to you, it is a great honor because yours really stood out and it stood out after looking at a marvelous, marvelous group."
Then he told Smoltz: "Sincere congratulations on a life well done."
Smoltz is the first Atlanta Braves to receive the award since Dale Murphy in 1988, and that former Braves great was recognized in Smoltz's acceptance.
"My whole career, it's never been about trying to achieve something like this; it's who I am," Smoltz said. "And it's what I believe the Atlanta Braves and baseball players in general represent. Negative sometimes sells and sometimes gets attention. And I can honestly say that this is a tribute to my teammates and myself and the Braves organization for giving me a chance to shine and make a difference.
"I get blessed to be with some great charity organizations, and because of that name on my back and the name on the front of my chest, I hope to represent it with what I consider the living guide that I played with. Dale Murphy is the guy that I think best exemplifies what baseball is about on and off the field, and I got a chance to play with him.
"Seeing everything about Roberto Clemente and hearing [my name associated with this award] just sends chills to know that I'm going to have this in my house, and have it a lot higher than the Cy Young, I can tell you right now."
Mark Newman is enterprise editor for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.