The study of motor development has traditionally focused on the timing and sequence of the acquisition of motor skills, such as sitting, crawling, or walking, over the first years of life. Because motor skills are directly observable, motor development serves as a useful exemplar for general principles of development. Current frameworks emphasize motor development in and as a context, such as how change in motor skill interacts with simultaneous change in other developmental domains, how the acquisition of new motor skills creates new opportunities for learning, and how the context in which motor development occurs shapes the course of development. For example, the onset of new motor skills changes the allocation of attentional resources, the quality of infants’ sleep, and available perceptual information. Reciprocally, contexts such as culturally specific parenting practices and individual differences in everyday experiences impact the timing and trajectory of new motor skills.