Context, a critical aspect of personalisation and human-computer interaction, is becoming increasingly significant with the proliferation of user-centric applications. The First ACM Workshop on Context Representation in User Modelling (CRUM 2023), organised in conjunction with the 31st ACM Conference on User Modeling, Adaptation and Personalization (UMAP 2023), provided a venue for research in the representation and utilisation of contextual information in intelligent systems. The workshop aimed to bring together researchers from various disciplines, including natural language processing, user modelling, explainable systems, and human-robot interaction and to facilitate conversation about the role of context in adaptive applications. The prospective authors were invited to submit papers of up to seven pages, four of which were accepted for publication and are introduced in this summary.