The House Budget Committee chairman, in his home district during a weeklong congressional recess, told a town hall-style meeting in Janesville he no longer opposes gay adoption, which he voted in 1999 to prohibit in Washington, D.C.
"Adoption, I'd vote differently these days," Ryan said in answer to a question. "That was, I think, a vote I took in my first term, 1999 or 2000.
"I do believe that if there are children who are orphans, who do not have a loving person or couple, I think if a person wants to love and raise a child, they ought to be able to do that. Period. I would vote that way," he said.
"I do believe marriage is between a man and a woman," he added.
In the 2012 U.S. presidential campaign, Republican nominee Mitt Romney said he supported gay adoption but Ryan, his running mate, did not say where he stood on the issue.
Ryan told WKOW-TV, Madison, Wis., he changed his mind about it a few years ago.
Ryan also told the town hall questioner he would vote in favor of the proposed Employment Non-Discrimination Act, which would prohibit sexual-orientation discrimination in hiring and employment by civilian, non-religious employers with at least 15 employees. He said a similar law already existed in Wisconsin.
But he said he would need to learn more about a transgender-inclusive version of the bill before deciding how he would vote on that.
President Barack Obama has said he supports the bill's passage.
The Human Rights Campaign, a large lesbian, gay, bisexual and transgender equal-rights advocacy group, did not immediately respond to a United Press International email request for a comment about Ryan's remarks. The group has generally given Ryan a zero percent rating on its legislative scorecard.