Mormons contributed a significant portion of funding to support Proposition 8, which would reverse a state Supreme Court ruling that laws against same-sex marriage violate the state Constitution. Voters approved the referendum but it is being challenged in court.
At an appearance in Hollywood last week to promote "Big Love," a show about polygamy that Hanks produces for HBO, the actor said there are "a lot of people who feel that (Mormon support for Proposition 8) is un-American, and I am one of them."
Mormon spokeswoman Kim Farah said "expressing an opinion in a free and democratic society is as American as it gets" and Bill McKeever of the Mormonism Research Ministry said it is "un-American to tell people that they shouldn't vote their conscience."
Hanks apologized for the comment in a statement released by a publicist, Fox said Friday.
"Last week, I labeled members of the Mormon church who supported California's Proposition 8 as 'un-American,'" the statement said. "But everyone has a right to vote their conscience; nothing could be more American.
"To say members of the Church of Jesus Christ of Latter Day Saints who contributed to Proposition 8 are 'un-American' creates more division when the time calls for respectful disagreement," Hanks said. "No one should use 'un-American' lightly or in haste. I did. I should not have."