Fungal has been proven a prolific producer of bioactive compounds enriched with secondary metabolites for therapeutic applications in preventing and curing several diseases. The research community has explored various sources and types of antioxidant fungi, ranging from soil-based to marine-based fungi, where the majority of the sources exhibit strong antioxidant properties. Numerous cultivation techniques for fungi, especially fermentations, have been developed and optimized with the aim of obtaining optimum yield with high quality of antioxidant compounds. This chapter elaborates on the sources and types of antioxidant fungi, the cultivation techniques applied in achieving high antioxidant yield together, with the cultural conditions affecting the targeted production. Several characterization methods used for fungal antioxidants are also elaborated, followed by their therapeutic applications in various health treatments. Fungi are forecasted to be one of the most wanted and useful biomasses due to their numerous advantages which will be widely used for maintaining general health in the future.