This article extends the coverage of the trust−acceptability model to a new situation of nuclear phase-out by investigating the effect of trust on the public acceptance of nuclear power, with South Korea as the research setting. Through the structural equation modeling of a nationwide survey dataset from South Korea, we examined the effects of the public’s trust in the various actors related to nuclear power on their perceptions of the benefits and risks of nuclear power and their acceptance of nuclear power. Contrary to previous studies’ findings, in South Korea, under a nuclear phase-out policy by the government, trust in government revealed a negative impact on the public acceptance of nuclear power. Trust in environmental non-governmental groups also showed a negative effect on nuclear power acceptance. In contrast, trust in nuclear energy authority and trust in nuclear academia both had positive effects. In all cases, the effect of a trust variable on nuclear power acceptance was at least partially accounted for by the trust’s indirect effects through benefit perception and risk perception. These findings strengthen the external validity of the trust−acceptability model and provide implications for both researchers and practitioners.