Physical activity (PA) prevalence among U.S. Latino/Hispanic adults of diverse backgrounds is not well known. This study describes PA among a representative sample of U.S. Latino/Hispanic adults. A population-based cohort of Hispanic/Latino adults (aged 18-74 years) participating in the Hispanic Community Health Study/Study of Latinos from March 2008 to June 2011 (N=16,415) was recruited in four urban areas from Miami, the Bronx, Chicago, and San Diego. Participants wore an Actical hip accelerometer for 1 week (n=12,253) and completed the Global Physical Activity Questionnaire (n=15,741). Data were analyzed in 2015. Based on accelerometry, Hispanics/Latinos engaged in 23.8 minutes/day (10.3 minutes/day when only considering minutes from sustained 10-minute bouts) of moderate to vigorous PA (MVPA). Individuals of Puerto Rican and Dominican background had the most minutes/day of MVPA (32.1 and 29.1, respectively), whereas those of Cuban background had the fewest (15.3). Based on the Global Physical Activity Questionnaire, 65% of Hispanic/Latinos met the aerobic component of 2008 Physical Activity Guidelines for Americans. Men and individuals of Puerto Rican background had the most minutes/day of leisure-time MVPA (30.3 and 30.2, respectively). Individuals of Puerto Rican and Dominican background had the most minutes/day of transportation-related PA (48.7 and 39.7, respectively). Individuals of Mexican and Central American background had the most minutes/day of work-related MVPA (90.7 and 93.2, respectively). Among Hispanics/Latinos, self-reported data provided information on the type of PA and helped explain variability identified from accelerometer-assessed PA. These findings highlight variability in PA among Hispanics from diverse ethnic backgrounds.