Sleep is an essential aspect of early childhood development. Adequate sleep is critical for various physiological and cognitive processes, such as memory consolidation, emotional regulation, and attention regulation. Infants’ and children’s sleep needs differ according to their age. Inadequate and low-quality sleep in infants may not only endanger their mental health but also lead to long-term adverse effects on cognitive, language, and even sensory-motor abilities. Therefore, knowing potential risk factors for sleep disorders is a foundation for preventing and then treating these problems in infants and assisting their parents in these efforts. In this chapter, we have provided an overview of normal sleep in infants and toddlers and its effects on neurodevelopment. We next evaluated the state of sleep disorders among infants and children and described interventions.