Oxylipins are a diverse class of oxygenated fatty acid derivatives that play pivotal roles in regulating physiological and developmental processes across eukaryotes. While extensively studied in plants and animals, their functions in fungi are emerging as equally vital, influencing growth, reproduction, and interspecies communication. Here, we review the synthesis and biological functions of endogenous oxylipins in filamentous fungi. Heme containing dioxygenases and non-heme containing lipoxygenases are the two best known classes of oxylipin synthetic enzymes found in fungi with the former typically found fused to a secondary cytochrome P450 domain. Studies, predominantly in Aspergillus, have revealed oxylipins to direct key morphological transitions in fungal development. While oxylipin synthetic enzymes appear to be found across higher fungi, their developmental roles are often specific to the genus and even species level. Finally, a growing body of work supports roles for oxylipins beyond development as important signals in virulence and stress response signaling of fungi.