Knowledge of how smartphone use in daily life, rather than in the context of intervention, may influence people’s behaviors and health is limited and mixed. The 2017 National Household Travel Survey (NHTS) data were used to examine the associations between daily smartphone use and several outcomes, including engaging in vigorous physical activity, self-perceived being healthy, and the adjusted mean differences for total trips and active travels among older adults (≥65 years) as well as among young and middle-aged groups (18–64 years), respectively. The prevalence of daily smartphone use declined with increasing age. Daily smartphone use was associated with increased total trips and active travel, a higher likelihood of engaging in vigorous physical activity, and in self-perceived being healthy status. The associations were stronger among older adults than young and middle-aged adults. More studies are needed to address the complex pathways among daily smartphone use and other outcomes. Daily smartphone use has the potential to address the unmet daily needs of older adults and bridge health disparities for this disadvantaged group.