Quality by design (QbD) is a systematic approach for the development of a product that begins with predefined objectives and emphasizes product, process understanding, and process control, based on sound science and quality risk management (QRM). Quality by design (QbD) has the potential to enhance performance, offer regulatory relief and adaptability, and bring about significant financial gains throughout the product life cycle. Due to its numerous advantages, the quality by design (QbD) method is now widely employed in the pharmaceutical industry. Prior to the development, this method provides a greater understanding of the process and the result, which eventually helps in the development of a higher-quality product. Formulation-based design (FbD) is under extensive investigation by budding scientists for better know-how of the product and process development for an unequivocal universal acceptance. Nowadays, the development of pharmaceutical products, biotechnological products, and new chemical entities using QbD and FbD techniques has resulted in the filing of various new drug applications and abbreviated new drug applications. This chapter focuses on the emergence of QbD and FbD as quality tools, applications of QbD and FbD in different fields and various regulatory guidelines, and hurdles in the implementation of QbD and FbD.