3-Methyl-1-butanethiol is primarily used as a flavoring agent in the food industry, where it imparts a distinctive sulfurous, onion-like, or garlic-like aroma. It is often added to processed foods, snacks, and seasonings to enhance flavor profiles. In the fragrance industry, it is utilized in small quantities to create specific notes in perfumes and colognes, particularly those aiming for a natural, earthy, or pungent scent. Additionally, it serves as an intermediate in organic synthesis, contributing to the production of various chemicals and pharmaceuticals. Its strong odor also makes it useful as a warning agent in natural gas and propane, helping to detect leaks effectively.