Little is known about how social participation can be facilitated among older adults in group physical activity and its psychosocial benefits that contribute to successful aging. This study aimed to understand older adults’ experiences with social participation in group physical activity programs. Using interpretive description methodology, 16 observations, eight focus groups, and two interviews with participants unable to attend focus groups were conducted with adults 55 years and older attending programs across four recreation facilities. Group programs were found to influence social participation through (a) a meaningful context for connecting and (b) instructors’ expectations of social interaction. Social participation in these programs addressed psychosocial needs by (c) increasing social contact and interaction, (d) fostering social relationships and belonging, and (e) promoting regular engagement. Training for instructors should include balancing the physical aspects of program delivery with the social, while also considering older adults’ diverse needs and preferences for social interaction.