Assumptions that single mothers are “time poor” compared with married mothers are ubiquitous. We tested theorized associations derived from the time poverty thesis and the gender perspective using the 2003–2012 American Time Use Surveys (ATUS). We found marital status differentiated housework, leisure, and sleep time, but did not influence the amount of time that mothers provided childcare. Net of the number of employment hours, married mothers did more housework and slept less than never-married and divorced mothers, counter to expectations of the time poverty thesis. Never-married and cohabiting mothers reported more total and more sedentary leisure time than married mothers. We assessed the influence of demographic differences among mothers to account for variation in their time use by marital status. Compositional differences explained more than two-thirds of the variance in sedentary leisure time between married and never-married mothers, but only one-third of the variance between married and cohabiting mothers. The larger unexplained gap in leisure quality between cohabiting and married mothers is consistent with the gender perspective.