Fungal spoilage in cultured dairy production poses significant challenges to product quality. This thesis provides science-based evidence to enhance the understanding of fungal contamination in cultured dairy production. This research encompassed the following key aspects: (i) characterizing the yeasts and molds commonly found on surfaces within the built environment of cultured dairy facilities and in spoiled products manufactured at those facilities, (ii) assessing how factors like production areas, types of swab sites, and seasons affect the diversity and distribution of fungi on the surfaces of cultured dairy facilities, and (iii) identifying the sources of contamination of Mucor circinelloides in cultured dairy production. These studies employed both traditional culture-based methods and molecular tools to provide comprehensive insights into fungal spoilage in the cultured dairy processing environment. Overall, these works provide important guidances that can support the development of strategies to minimize fungal spoilage in cultured dairy industry.