What was surprising is the Indianapolis Colts' quiet coach shared his position publicly, sparking discussion about the impact of the Super Bowl winner's comments.
Dungy caused a stir Tuesday when he accepted the "Friend of Family" award from the conservative Indiana Family Institute.
The coach told the audience he supported the group's efforts to amend the Indiana constitution to define marriage as between one man and one woman.
"I appreciate the stance they're taking, and I embrace that stance," Dungy told the crowd of about 700 people.
Dungy said his comments should not be considered gay bashing.
"We're not trying to downgrade anyone else. But we're trying to promote the family - family values the Lord's way," Dungy said.
Colts president Bill Polian was at NFL meetings in Phoenix on Thursday and was unavailable for comment.
"Coach Dungy's feelings on the importance of marriage and family are well known to the overwhelming majority of American sports fans," said Myra Borshoff Cook, a spokeswoman for Colts owner Jim Irsay. "He, of course, is free to speak to any group he wishes. The club does not take positions in political issues in which it is not directly involved."
Supporters of the proposed ban hailed the endorsement.
"That was sort of a double for us," said Curt Smith, president of the institute, which is associated with but independent of James Dobson's "Focus on the Family" group.
Smith said he was unaware Dungy, who received the award because of his pro-family ethic, not for his views on public policy, would address the issue.
The resolution's sponsor, Sen. Brandt Hershman, R-Monticello, said Dungy's endorsement made the proposal more credible.
"I certainly appreciate him being able to step forward and speak out strongly in his beliefs," Hershman said.
The NFL sought to distance itself from the matter.
"Coach Dungy is speaking for himself and expressing his views, which he is fully entitled to do," league officials said in a statement. "No doubt there are people in our league that have a different view. We respect the right of employees to have and express their views and don't regulate the political or religious views of team or league employees."