Data from the U.S. Religious Landscape Survey, conducted by the Pew Research Center’s Forum on Religion & Public Life, shows that many marriages are between people of different religious faiths. According to the survey, Buddhists and the religiously unaffiliated are the most likely to have a spouse or partner with a different religious background, while Mormons and Hindus are the least likely to marry or live with a partner outside their own faith.
[For more info on each religion’s view of interfaith marriage, read the Wiki article.]