Purpose Supervised exercise is a potentially promising supportive care intervention for people with metastatic breast cancer (MBC), but research on the patients’ perspective is limited. The aim of the current focus group study was to gain an in-depth understanding of MBC patients’ perceived barriers, facilitators, and preferences for supervised exercise programs. Methods Eleven online focus groups with, in total, 44 MBC patients were conducted in four European countries (Germany, Poland, Spain, Sweden). Main topics of the semi-structured discussions covered attitudes towards participation in supervised exercise programs, perceived facilitators, experienced barriers, and exercise preferences. Interviews were transcribed verbatim, translated into English, and coded based on a preliminary coding framework, supplemented by themes emerging during the sessions. The codes were subsequently examined for interrelations and re-organized into overarching clusters. Results Participants had positive attitudes towards exercise, but experienced physical limitations and insecurities that inhibited their participation. They expressed a strong desire for exercise tailored to their needs, and supervision by an exercise professional. Participants also highlighted the social nature of group training as an important facilitator. They had no clear preference for exercise type, but rather favored a mixture of different activities. Flexible training modules were considered helpful to increase exercise program adherence. Conclusions MBC patients were generally interested in supervised exercise programs. They preferred group exercise that facilitates social interaction, but also expressed a need for individualized exercise programs. This suggests the relevance to develop flexible exercise programs that are adjusted to the individual’s needs, abilities, and preferences.