Seventeen percent of Americans who are married or living with a partner say their spouse or partner has a different religious affiliation than they do, according to PRRI’s spotlight on family religious dynamics and interfaith relationships. That’s roughly one in six couples living the reality that wedding vows, family holidays, and eventually a child’s upbringing all have to be negotiated across two different belief systems rather than assumed to run on the same track. A separate 2025 analysis from Pew Research Center’s Religious Landscape Study puts the number even higher, at 26%, once it counts differences between Christian denominations as well as differences between faiths entirely. However the line gets drawn, the underlying picture is the same: sharing a religion with your spouse is common, but it is nowhere near universal.
Interfaith rates swing hard by religious group
PRRI’s data shows the 17% overall figure hides a lot of variation underneath it. Twenty-seven percent of non-Christian Americans are in interfaith relationships, the highest share of any group measured. White Catholics and religiously unaffiliated Americans both come in at 22%, Hispanic Catholics at 19%, and white mainline Protestants at 18%. The rate drops considerably for Black Protestants, at 10%, and drops again for white evangelical Protestants, at just 7%. Pew’s separate breakdown backs up the same general shape: Latter-day Saints are the most likely to marry within their faith at 87%, Protestants marry other Protestants 81% of the time, and Catholics marry other Catholics 75% of the time, while only 65% of Jewish respondents and 68% of unaffiliated Americans have a spouse who shares their identity.
The harder question is what happens with the kids
Where PRRI’s research gets more interesting is in what happens once children enter the picture. Eighty-four percent of white Christian parents expect their children will grow up to share their religion, and 79% of Christian parents of color say the same. Religiously unaffiliated parents are far less confident their kids will land in the same place: only 46% expect their children to hold similar religious views, though 82% expect their kids will end up non-religious or secular as adults, compared to just 24% of white Christian parents and 27% of Christian parents of color who expect that outcome for their own children. In other words, unaffiliated parents are less certain their kids will end up exactly like them, but far more confident their kids won’t end up religious at all — a distinction that matters enormously for how interfaith couples plan a child’s upbringing.
This isn’t a new phenomenon confined to one generation figuring it out for the first time. PRRI found that 21% of Americans report their own parents or guardians came from different religious backgrounds, meaning a meaningful share of today’s interfaith couples grew up inside a mixed-faith household themselves and are repeating, or consciously revising, the approach their own parents took.
Faith commitment, not faith identity, predicts the odds
One of PRRI’s more useful findings for anyone trying to predict their own odds has less to do with which religion someone belongs to and more to do with how often they practice it. Among Americans who seldom or never attend religious services, 22% are in an interfaith relationship. Among those who attend weekly, that number drops to just 8%. Regular religious practice tends to concentrate people inside communities, congregations, and social circles built around a shared faith, which naturally narrows the dating pool to people who already believe similarly. Loosen that practice, and the dating pool — and the marriage pool that follows it — opens up considerably.
None of this data suggests interfaith marriage is a problem to be solved or a risk to be managed. It suggests something closer to the opposite: a large and growing share of American families have already found a way to build a shared life without a shared theology, raising kids who will grow up watching two different traditions coexist under one roof rather than assuming faith only comes in one flavor.
What the numbers make clear is that the couples navigating this successfully aren’t relying on luck. The lower interfaith rate among weekly worshippers versus the higher rate among the less observant points to a simple mechanism: proximity and shared practice make sameness easier, and their absence makes difference far more likely to walk through the door in the form of someone you love. For the one in six married Americans already living that difference, the PRRI data suggests the relationship itself isn’t the hard part. The harder, more interesting work is the ongoing conversation about what gets passed down to the next generation, and increasingly, American families are proving that conversation doesn’t require agreement to succeed.
