Citrus essential oils (CEOs) are a mixture of volatile compounds consisting mainly of monoterpene hydrocarbons and are widely used in the food and pharmaceutical industries because of their antifungal activities. To face the challenge of growing public awareness and concern about food and health safety, studies concerning natural biopreservatives have become the focus of multidisciplinary research efforts. In the past decades, a large amount of literature has been published on the antifungal activity of CEOs. This paper reviews the advances of research on CEOs and focuses on their in vitro and food antifungal activities, chemical compositions of CEOs, and the methods used in antifungal assessment. Furthermore, the antifungal bioactive components in CEOs and their potential mechanism of action are summarized. Finally, the applications of CEOs in the food industry are discussed in an attempt to provide new information for future utilization of CEOs in modern industries.