As research of self-identity, self-concept, and self-efficacy in the discourse of environmental education is scarce, this study attempted to explore the role of visitors' self-identity in marine museum learning. With the use of on-site data collection, investigators of this study collected 144 completed questionnaire surveys from marine museum visitors. Seventeen of these visitors were randomly selected and agreed for an individual 30-minute follow-up interview to solicit their views of environmental awareness and responsibility. Results revealed that visitors who viewed themselves as explorer/facilitator (E&F) outperformed visitors who viewed themselves as experience seeker/recharger on self-concept and self-efficacy. In addition, E&F visitors tended to have a better understanding of conservation, sustainability, human-nature interaction, and science communication. All visitors did possess similar levels of interest and enjoyment during their museum visit. The above results provide insights into the important role of self-identity in the learning outcomes of self-concept, self-efficacy, and environmental awareness and responsibility among museum visitors.