Purpose: Examine objectively measured environmental correlates of physical activity and sedentary behavior in toddlers (12–35 mo). Methods: Participants were recruited at immunization appointments in Edmonton, Canada. Physical activity and sedentary time were objectively measured via accelerometers (n = 149). The parents reported screen time and demographic characteristics via a questionnaire (n = 249). Postal codes were used to link neighborhood data via geographic information systems. Neighborhood data included 4 environmental domains: functional (ie, walkability), safety (ie, crime), esthetic (ie, tree density), and destination (ie, cul-de-sac density, wooded area percentage, green space percentage, recreation density, park density). Weather data (temperature and precipitation) were obtained via historical weather records. Multilevel multiple linear regression models were used to account for clustering of participants within neighborhoods and adjustment of demographic variables. Results: Each additional 10°C of mean temperature was significantly associated with 5.74 (95% confidence interval, 0.96–10.50) minutes per day of higher light-intensity physical activity, though the effect size was small (f 2 = 0.08). No other significant associations were observed. Conclusions: The lack of significant findings for neighborhood environment factors suggests proximal factors (eg, features of the home environment) may be more important in predicting toddlers’ physical activity and sedentary behavior. More indoor physical activity opportunities may be needed on colder days for toddlers.