Thiols can react with readily available organic substrates under benign conditions, making them suitable for use in chemical, biological, physical, and materials and engineering research areas. In particular, the highly efficient thiol-based click reaction includes the reaction of radicals with electron-rich enes, Michael addition with electron-poor enes, carbonyl addition with isocyanate S 2 ring opening with epoxies, and S 2 nucleophilic substitution with halogens. This mini review provides insights into emerging venues for their industrial applications, especially for the applications of thiol-ene, thiol-isocyanate, and thiol-epoxy reactions, highlighting a brief chemistry of thiols as well as various approaches to polythiol synthesis.