Lifelong education for dietitians in Japan is based mainly on competencies according to years of experience. Because learning content differs depending on the desired position and specialty, training programs that reflect the individual learning needs of public health dietitians are needed. This study aimed to assess the individual learning needs of public health dietitians via years of experience in health promotion. In 2021, an online survey of public health dietitians involved in health promotion in prefectures, designated cities, and other municipalities throughout Japan was conducted. Years of experience in health promotion were categorized as early (<10 years), mid-career (10–19 years), and leadership (≥20 years) periods. To ascertain individual learning needs, the survey asked about respondents’ desired final position, career path, and skills they felt they needed to improve in the future. Of the 1649 public health dietitians analyzed, all administrative categories preferred to work as public health generalists in mid-career or leadership periods rather than in the early period. In municipalities, more public health dietitians across all experience categories selected “professional competence”, such as knowledge in specialized areas and nutritional guidance techniques. It was suggested that public health dietitians in the mid-career and leadership periods have individual learning needs, in both nutrition specialists and public health generalists.