Aim Food security and sufficient nutrient intake are critical to longevity and active aging. The present study aimed to elucidate physical and social factors related to dietary variety among single‐living older adults in Japanese communities. Methods The cross‐sectional survey with a self‐administrated questionnaire was carried out for all older adults living alone aged 65 years and older in three cities of Japan during 2014. Dietary variety score (DVS) was determined by counting the number of 10 food groups consumed at least once in 2 days using a food frequency questionnaire. Using the data of 704 men and 1366 women, the sex‐specific association of low DVS (<4) with age, region, frailty, annual income, social support, distance to the nearest supermarket and car ownership was analyzed. Results The prevalence of low DVS was 40.9% for men and 18.4% for women. Frailty and low social support were associated with low DVS. A gradient association with income was found for women, whereas men showed a threshold: <1.5 million yen per year was associated with low DVS. The distance to the nearest supermarket was not significantly associated with DVS. Conclusions The findings of the present study imply that as well as frailty, poor social support and economic disadvantage are associated with a decline in dietary variety. In particular, frail men with income <1.5 million yen per year had a high risk of decreased dietary variety. Formal and informal support to secure food accessibility for physically and socially vulnerable older adults should be encouraged. Geriatr Gerontol Int 2017; ••: ••–••.