Background: Whereas children's active travel to school (ATS) has confirmed benefits, only a few large national surveys of ATS exist. Methods: Using data from the Health Behavior in School-aged Children (HBSC) 2009-2010 US survey, we conducted a logistic regression model to estimate the odds ratios of ATS and a linear regression model to estimate the adjusted mean differences of the percentage of ATS within a school. Results: Overall, 21.4% of children engaged in at least one way of active travel to or from school. ATS was less common for trips to school than from school. Greater distance to school was a major barrier preventing children from ATS. Children living in large cities were more likely to engage in ATS, and schools located in a large city had higher proportions of ATS rate. Children having lower family satisfaction, or engaging in a greater number of physically active days during the past week were all more likely to engage in ATS. Conclusions: Although ATS is low among US children, significant variation exists. HBSC is a promising data source for an ATS study. As the first study to explore the variation of ATS at school level, this research contributes uniquely to current knowledge.