The Three Teachings of East Asia (TTEA) inventory was created to assess the extent to which respondents endorse or align with key tenets of Buddhism, Taoism, and Confucianism. Thus, the 69-item TTEA inventory assesses 20 distinct tenets, including 7 representing Buddhism (not-self, impermanence, interconnectedness, active karmic view, punishing karmic view, meditation, and mindfulness), 5 representing Taoism (embracing contradiction, noninterference, Ziran, cyclic nature, and tranquility), 5 restrictive tenets of Confucianism (propriety pressure, intrinsic propriety, relational hierarchy, interpersonal harmony, and conforming to social norms), and 3 empowering tenets of Confucianism (self-cultivation, leading by example, and human heartedness). A shorter 36-item version of the TTEA (2 items per subscale) was also developed and validated. The TTEA inventory was developed from a pool of 122 items given to a cross-cultural sample of 2091 online respondents (322 Chinese, 688 White Americans, 319 Asian Americans, 400 Japanese, and 362 Taiwanese). Items were selected using exploratory factor analyses (EFAs). The final items demonstrated a stable factor structure of 20 subscales forming four higher-order composites representing ideologies. However, two of the Buddhism subscales (impermanence and mindfulness) cross-loaded across several ideology factors and were therefore excluded from further validation. The TTEA inventory demonstrated partial scalar invariance, suggesting that scores could reasonably be compared across the five cultural groups. The TTEA subscales also demonstrated high levels of internal consistency in both men and women within each of those five cultural groups. The TTEA also demonstrated discriminant validity with a range of related constructs as well as unique predictive validity. Thus, the TTEA inventory offers one of the first comprehensive, multilingual measures of Eastern ideologies.