Looking at the activities linked with the design, production, and consumption of fashion, it is important to note that the range of actors who interact with the fashion sector has been developing over time, and is not limited to commercial or strictly education-oriented stakeholders but may include diverse non-profit organisations. As such, in recent years museums have become increasingly active participants in the fashion ecosystem, broadening their engagement with fashion beyond traditional collection and research-oriented activities. Drawing on museum collections, the knowledge and expertise of their staff or the uniqueness of museum buildings and sites, such institutions, may therefore become important spaces of education, reflection on, inspiration for, presentation, and promotion of fashion involved in the broader notions of fashion curation. The growing importance of museums as stakeholders in the fashion market is reflected in the establishment of specialist fashion-focused institutions, more prominence given to the subject in museums with diverse profiles and the broader paradigmatic change in the approach to the subject of fashion from a focus on collecting garments and costumes (museums of costume, dress museology) to a broader fashion orientation (museums of fashion, fashion museology). This development is much in line with the more general call for deeper interactions and engagement between museums and their environment (including educational institutions, local communities, and the commercial sector) in the spirit of the new museology but may also be driven by museum marketing or fashion marketing objectives. Many Polish museums seem to very well reflect this paradigmatic change. Therefore, this chapter analyses fashion-related activities undertaken by Polish museums in 2019–2021. Their intensity was assessed on the basis of a nationwide museum survey designed and conducted by the authors in 2022. Different kinds of museum fashion-related activity types and museum partners are distinguished and discussed, in particular fashion designers and fashion firms, educational institutions, and non-governmental organisations. The text also considers the problem of the external funding of fashion-oriented museum activities and the spatial distribution and factors behind leadership among Polish museums with respect to their engagement in fashion-related endeavours.