High-grade serous ovarian carcinoma (HGSOC) is a polyclonal disease characterised by the presence of subclones with distinct cancer genotypes. This intratumoural heterogeneity is linked to recurrence, chemotherapy resistance, and overall poor prognosis. For one patient sample we used NanoString CosMx Spatial Molecular Imaging (SMI) to analyse the organisation of tumour subclones and the cells that comprise their niche at single cell resolution. This dataset contains the related data and analysis scripts. Our study highlights the high degree of subclonal heterogeneity in HGSOC and that subclone-specific ligand and receptor expression patterns likely modulate how these tumour cells interact with their local microenvironment.