The purpose of this study was to investigate adult attitudes on distances children should be allowed to travel to places and play in outdoor areas without adult supervision, with consideration of differences in adult attitudes by socio-demographics and urbanisation. In 2013, Australian adults (N = 1293) were asked what distances children aged 8–12 years should be allowed to walk/cycle to places, and play outdoors without adults. Descriptive analyses and chi-square tests were conducted to assess adult attitudes on children’s independent mobility range. Overall, 62% of adults would restrict children’s independent travel to places <500 m from home, and 74% would restrict independent outdoor play <500 m from home. Women and adults with lower education were more likely to report restrictive attitudes than men and adults with higher education, respectively. The promotion of active travel and outdoor play in children may require increasing adults’ acceptance of greater independent mobility range.