Objectives: This is a cross-sectional investigation of living arrangements, social contacts, and level of leisure-time physical activity (LTPA) among residents of Sonoma, California, aged 55 and older. Methods: The odds of different levels of LTPA were assessed by living arrangements and social contacts following adjustment for measures of health, functioning, physical performance, selected health behaviors, and socioeconomic status for men and women separately (n = 2,073). Level of LTPA also was examined among married couples only (subset of sample, n = 511 spouse pairs). Results: The relationship between living arrangements, social contacts, and LTPA varied by gender and level of LTPA. Among married couples, the LTPA of the partner was the most significant predictor of the LTPA of the participant, with the exception of those who engaged in less than brisk activity. Discussion: Living arrangements and social contacts are important determinants of LTPA and should serve as the basis for future interventions.