Despite the pervasiveness of Catholicism among Latinos, studies reveal an increasing shift toward Protestantism. Examining the relationship between religion and ethnicity, we explore homeland language use as a core ethnic marker using a survey from the Pew Hispanic Center. Results reveal that Catholic Latinos are significantly more likely to use Spanish at home, even after controlling for other key variables. In response, we posit that Latino Catholicism and Protestantism entail significantly different religiosities in both home and host countries that impact Latino ethnic identification and its markers such as language use. Catholicism displays a higher level of inculturation in the sending country and greater overt institutional acceptance of ethnic culture in host countries. Protestantism in Latin America breaks with localized religiosity and traditions, and U.S. Protestant congregations may de-emphasize ethnic culture in their theologies and worship. Hence, Latino Catholicism acts as a bridge to homelands and reinforces ethnic salience, thereby supporting continued Spanish use at home. In contrast, Protestants embrace a reorienting religiosity that often presides over ethnic identification, decreasing the salience of homeland cultural markers.