Excipients play a critical role in the formulation of pediatric medications, impacting both safety and efficacy. The challenge lies in recognizing that not all excipients are innocuous bystanders; some have raised concerns about their potential impact on the growth and development of young patients. This chapter provides a comprehensive overview of excipients, focusing on their unique considerations for the pediatric population. Key sections cover the physiological characteristics of children that influence excipient selection, including their developing organ systems, metabolism, and absorption pathways. The chapter also addresses the potential for excipient toxicity, particularly in neonates and young children, and explores the regulatory frameworks that guide excipient use in pediatric formulations. Excipient interactions within dosage forms, especially with active pharmaceutical ingredients, are discussed to highlight stability and performance considerations. Finally, an overview of the most commonly used excipients in pediatric products is provided, emphasizing their roles in improving palatability, dosage accuracy, and overall drug acceptability for young patients. This chapter aims to guide formulators and regulatory professionals in making informed decisions when developing safe and effective pediatric medications.