BACKGROUND Consumption of low-calorie sweeteners (LCSs) has increased markedly during the past several decades, yet the prevalence of LCS consumption in recent years is currently unknown. OBJECTIVE The aim of this study was to describe LCS consumption in the United States and to characterize consumption by sociodemographic subgroups, source, frequency, eating occasion, and location. DESIGN Cross-sectional study using National Health and Nutrition Examination Survey data from 2009 to 2012. The prevalence of LCS consumption was assessed using two 24-hour dietary recalls, while the frequency (number of times per day), occasion (meal vs snack vs alone), and location of LCS consumption (at home vs away from home) was assessed using data from the one, in-person, 24-hour dietary recall. PARTICIPANTS National Health and Nutrition Examination Survey participants (2 years old or older) either in 2009-2010 (n=9,047) or in 2011-2012 (n=7,939). After excluding participants with implausible energy intake (n=44), the final sample size was 16,942. MAIN OUTCOME MEASURES The primary outcome was the proportion of individuals consuming one or more foods, beverages, or packets containing LCSs during at least one of their two dietary recalls. STATISTICAL ANALYSES PERFORMED Data were weighted to provide national estimates and Stata frequency procedures for complex survey design were used for all analyses. RESULTS Our findings were that 25.1% of children and 41.4% adults reported consuming LCSs. Most LCS consumers reported use once daily (80% of children, 56% of adults) and frequency of consumption increased with body weight in adults. LCS consumption was higher in females compared with males among adults, and in obese individuals, compared with overweight and normal-weight individuals. Individuals of non-Hispanic white race/ethnicity also had higher prevalence of consumption compared with non-Hispanic blacks and Hispanics and those in the highest tertile of income had higher LCS consumption compared with individuals of middle or low income across LCS product categories in adults, and for LCS beverages and LCS foods in children. Most LCS consumers reported consuming LCS with meals (64% of adults, 62% of children) and the majority of LCS consumption occurred at home (71% and 72% among adults and children, respectively). CONCLUSIONS LCS consumption is highly prevalent in the United States, among both children and adults. Well-controlled, prospective trials are required to understand the health impact of this widespread LCS exposure.