Dance is a universal human behavior, and a crucial component of human musicality. What drives and limits the earliest ages dance can appear? We aimed to characterize infants' earliest dance behavior, asking: When do infants begin to spontaneously dance to music, and how variable is this age of onset? What predicts whether an infant can dance: Is this simply a function of gross motor development? Does the nature of infants’ dance change over the first two years, or remain stable? Parents of infants age 0-24 months (N=276) completed an online survey to characterize their infants’ dance behavior. We asked parents to consider movements that were produced by the child, occurred more when music is playing, and “looked like dance, to them”. We found that dance begins early in life, and at a wide range of ages across individuals: from 2 to 20 months (*M *= 9.4m). Once children can dance, they dance frequently, as a near-daily part of their behavioral repertoire. Motor development was not a major determinant of ability to dance: It did not account for more variance than age alone. Infants’ dance changed dramatically with age: For example, infants increasingly used iconic gestures, and danced more frequently. These data provide an initial characterization of the developmental origins of dance, informing broad questions about the origins of human musicality and highlighting the prominent role of dance behavior in infancy. ᐧ