BackgroundWe examined the correlations between living arrangement and the physical activity (PA) levels of youth aged 9–19 years while accounting for demographic factors such as age, sex, and socioeconomic status in Shanghai, China.MethodsCross-sectional analyses of data from the 2014 Physical Activity and Fitness in Shanghai China—The Youth Study was conducted. Participants were 33,213 primary (9–11-year-olds; n = 13,237), junior middle (12–14-year-olds; n = 11,157), and junior high school students (15–19-year-olds; n = 8819). Youth (boys = 49%) and their guardians were randomly sampled from 17 districts in Shanghai, China. Youths’ moderate-to-vigorous PA (MVPA) levels, information about living arrangement, and guardians’ sociodemographic factors were collected via questionnaires.ResultsOnly 17.8% of school-aged youths in Shanghai met MVPA recommendations, with significantly more boys (20.6%) meeting recommendations than girls (p < .001). Youths living in rural areas showed an overall significantly higher percentage of meeting MVPA recommendations (20.3%) than those living in urban areas (p < .001). Youths who lived with single parents showed an overall significantly lower percentage of meeting MVPA recommendations (15.3%) than those living with their grandparent(s) or with both parents (p < .001). A logistic regression analysis revealed that, among 9–11-year-olds, children who live with their grandparent(s) were less likely to meet MVPA recommendations than those who lived with both parents (boys: adjusted odds ratio (aOR) = 0.72, 95% confidence interval (CI) = 0.61–0.84; girls: aOR = 0.84, 95%CI = 0.72–0.98).ConclusionsType of living arrangement was associated with the PA of youth in Shanghai, with no significant gender difference. Youth aged 9–19 years who lived with single parents had the lowest percentage of meeting MVPA recommendations. The probability of achieving 60 min/day MVPA recommendations was significantly lower among 9–11-year-old children living with their grandparent(s) than children living with both parents; however, no such difference was observed among adolescents. Our findings suggest that living arrangement may be an important consideration for promotion of PA among youth in China.