Dandelion ( genus) is a perennial herb belonging to the Asteraceae family. As a well-known and extensively studied genus, dandelion comprises numerous species. Some species have been widely used in both complementary and alternative medicine to clear heat, detoxify, activate blood circulation, dispel stasis, and discharge urine. Multiple pharmacological studies have highlighted its therapeutic potential, including anti-bacterial, anti-oxidant, anti-cancer, and anti-rheumatic activities. Furthermore, bioactive compounds associated with these effects include sesquiterpenoids, phenolic compounds, essential oils, saccharides, flavonoids, sphingolipids, triterpenoids, sterols, coumarins, etc. Based on recent studies about the genus, the present review critically evaluates the current state of dandelion utilization and summarizes the significant roles of dandelion and its constituents in different diseases. We also focus on the reported phytology, chemical composition, pharmacology, and toxicity of dandelion, along with the main possible action mechanisms behind their therapeutic activities. Meanwhile, the challenges and future directions of the genus are also prospected in this review, thus highlighting its pharmaceutical research and practical clinical applications.