 The COVID-19 pandemic has led to changes in physical activity, PA, and sedentary behavior, SB, among U.S. children. A study conducted by parents and legal guardians of U.S. children between April 25 to May 16, 2020 found that children engaged in about 90 minutes of school-related sitting and over 8 h of leisure-related sitting a day. The most common physical activities during the early COVID-19 period were free play unstructured activity, running around, tag, 90% of children, and going for a walk, 55% of children. Parents of older children perceived greater decreases in PA and greater increases in SB from the pre- to early COVID-19 periods. Children were more likely to perform PA at home indoors or on neighborhood streets during the early versus pre-COVID-19 periods. About a third of children used remote streaming services for activity classes and lessons during the early COVID-19 period. The study suggests that short-term changes in PA and SB may become permanently entrenched, leading to increased risk of obesity, diabetes, and cardiovascular disease in children. Programmatic and policy strategies should be geared towards promoting PA and reducing SB over the next 12 months. This article was authored by Genevieve F. Dunton, Bridget Du, and Shaleen D. Wang. We are article.tv, links in the description below.