Previous research within and beyond positive psychology has informed us that one’s perception of self and others is critically important to one’s psychological well-being. Cultural psychology research suggests that the dynamic of ‘self and others’ plays out differently in different cultures. This study empirically measured the associations amongst self-acceptance, other-acceptance, and well-being, and investigated whether different cultural affiliations (operationalized as Korean versus U.S. cultures) modifies the associations among these key constructs. Two hundred thirty-two participants (150 Korean, 61 U.S., 21 other nationality) completed a series of measures in English or Korean. T-tests and Z-tests compared mean level values and correlation strengths between Korean and U.S. participants. The degree of self-acceptance was similar in the Korean and the U.S. samples, whereas the degree of other-acceptance and well-being was significantly higher among the U.S. participants. Self-acceptance, other-acceptance, and well-being were positively correlated with one another. Moderation analyses were non-significant, but trend analyses suggested that self-acceptance and well-being association was stronger for the Koreans than for the U.S. participants, whereas that between other-acceptance and well-being was stronger for the U.S. participants. Findings suggest that broad generalization resulting from a simple dichotomy between cultures may not be appropriate. Still, culture is a highly important socioecosystem in which the issue of well-being should be studied. Thus, further investigations that consider both between and within culture variations are needed.