This study investigated heritage language (HL) maintenance and ethnic identity among Korean heritage speakers in the Pacific region (Australia, New Zealand, and Hawaii), an understudied population in the field. It focused on patterns of language use and factors (i.e. age at immigration (AI), self-rated language proficiency, and frequency of language use) influencing Korean heritage speakers' self-defined identity. A total of 167 Korean immigrant adults aged 18-40 completed an online survey regarding their HL (i.e. Korean) and majority language (ML) (i.e. English) use in everyday contexts (e.g. with family members and at work), their self-rated HL and ML proficiency, and their sense of identity. The survey results showed high HL use with parents/grandparents at home, high self-rated HL proficiency, and a strong sense of identity as Korean, among participants across the three locations. However, as with other ethnic minority communities, they tended to use ML more than HL in most of their daily activities, and with their siblings and friends, indicating a perceptible shift towards ML. This supports the findings of previous studies conducted in North America. Notably, this study found that AI was significantly correlated to the participants' self-identification. Regional differences were discussed, along with recommendations for future research.