Nearly one in four students residing in the United States is from an immigrant family and these children's school readiness is related to their parent's nativity and other sociodemographic characteristics. Social-emotional skills are an important conduit for academic development, yet these relations have not been explored for children from immigrant families. This study utilized the Early Childhood Longitudinal Study--Kindergarten Class of 2010-2011, a nationally representative sample of 13,400 students in the United States, to compare the social-emotional development of kindergarten students from immigrant and nonimmigrant families, and to determine the relations of social-emotional functioning to kindergarten achievement. Results indicate elevated social-emotional functioning among children from immigrant families, particularly those who emigrated immigrated from Mexico, compared with children of U.S.-born parents. Parent nativity predicted reading achievement, but not mathematics performance, even when controlling for sociodemographic factors and social-emotional skills. This study suggests an immigrant advantage in early social-emotional development. Implications for research and practice are discussed.