Background: Evidence for the effects of exercise and vitamin D supplementation on quality of life (QoL), fear of falling (FoF) and mental wellbeing in older adults is conflicting. Objective: To study the effects of vitamin D supplementation and multimodal group exercise on psychosocial functions of wellbeing, including QoL, mental wellbeing and FoF. Method: This is a 2-year, double-blind, placebo-controlled vitamin D and open exercise intervention trial with 409 older Finnish women (70-80 years of age) randomized to 4 treatment arms: (1) placebo without exercise, (2) vitamin D (800 IU/day) without exercise, (3) placebo and exercise, and (4) vitamin D (800 IU/day) with exercise. Exercisers participated in group exercise twice per week for 12 months and once per week for the subsequent 12 months, plus home exercises. Results: When comparing with the placebo without exercise group, there were no statistically significant differences between groups receiving either vitamin D, exercise or both treatments for changes in QoL or mental wellbeing (although a slight decline was seen in mental wellbeing in those receiving vitamin D only, p = 0.044). The initial slight reduction in FoF was significant in all intervention groups compared with controls (p < 0.05), but this was only temporary. Conclusion: Neither vitamin D nor exercise contributes to better QoL, FoF or mental wellbeing in community-dwelling healthy older women with sufficient vitamin D levels.