In microbiome research, the mycobiome component remains relatively understudied. The oral cavity harbors a diverse range of fungal species, many of which are implicated in disease. Among them, Candida albicans has been abundantly detected in microbiome studies, with its interspecies interactions with bacterial species extensively documented. This chapter provides a comprehensive overview of current research on the oral mycobiome and its association with various oral and systemic diseases. Additionally, it highlights the role of fungal species in the oral cavity, with particular emphasis on Candida albicans as a key contributor to oral biofilm formation and its interactions with bacterial communities.