Social support is a key component in facilitating initiation and adherence to physical activity, as it may provide increased motivation (Eyler et al., 1999). The purpose of this study was to investigate the effect of a 12-week exercise and balance training program on social support in older adults. Participants (women = 212, men = 81; Mage = 68.3 Â±6.42 years) were community dwelling older adults free from neuromuscular conditions. They were randomly assigned to either an exercise group or control group. The exercise group completed a 12-week exercise program, consisting of 3 weekly exercise sessions in accordance with Canadian physical activity guidelines; the control group was instructed to continue their normal activities. Social support was assessed at the beginning and end of 12 weeks. The exercise program was based on social cognitive theory, designed to foster self-efficacy and social support through both peers and student trainers. Two separate repeated-measures ANOVAs were conducted to determine if there were group differences in social support from baseline to follow-up testing. There was a significant group-by-time interaction for both peer social support, F (1, 292)= 11.87, p<0.01 and expert social support, F (1, 292) = 12.65, p<0.01. Paired sample t-tests showed that both peer and expert social support significantly increased in the exercise group, with no change in the control group. These findings indicate that both peers and trainers can be effective at fostering social support in older adults, which may be a simple and inexpensive way to positively impact exercise behaviours in seniors.