AbstractThis paper unites disparate literature to test the influence of religious belonging and behavior characteristics along with secular welfare boundaries on anti‐immigrant attitudes. We suggest that welfare states varied in their religious foundations during the transition from religious‐based solidarity to modern state‐based solidarity and formulate a novel analytical framework to hypothesize effects across individuals and welfare regime types. Using eight waves of the European Social Survey (2002–16), we find that religious effects are strongest in welfare states with the most religious foundations, the Southern European welfare states, and weak in the universalist welfare states, which lacked historical state‐church tensions. Other welfare types show a mix of religious effects, with some challenging expectations. Furthermore, Christian majority membership is often associated with heightened anti‐immigrant attitudes, most consistently in contrast to the non‐Christian minority. For welfare‐based forms of inclusion, we find consistent institutional trust effects and two competing logics for secular boundaries: a propensity for welfare chauvinism and a culture of inclusion.