Language is a fundamental aspect of human culture that influences cognitive and perceptual processes. Prior evidence demonstrates personality self-report can vary across multilingual persons' language contexts. We assessed how cultural identification, language dominance, or both dynamically influence bilingual respondents' self-conception, via self-reported personality, across English and Spanish contexts. During separate English and Spanish conditions, 133 Hispanic/Latino bilingual participants (70 female) completed the Big Five Inventory of personality. We used language use and acculturation surveys completed in both languages to calculate participants' relative language dominance and identification with U.S.-American and Hispanic culture. Participants reported higher levels of agreeableness, conscientiousness, and neuroticism in English relative to Spanish. Language dominance predicted cross-language differences in personality report, with higher extraversion reported in participants' dominant language. Within each language, greater endorsement of U.S.-American identity was associated with higher extraversion and conscientiousness and lower reported neuroticism. Agreeableness report in both languages was positively predicted by Hispanic identification. Our results clarify existing literature related to language and cultural effects on personality report among U.S. Hispanics/Latinos. These findings could inform assessments of self-relevant cognitions across languages among bilingual populations and hold relevance for health outcomes affected by cultural processes.