Psychosocial resources such as optimism and social resources are associated with adaptation, age-related changes and life satisfaction (LS) maintenance. The relationship between optimism, social resources and LS is unclear as this issue has not been addressed by many studies. The present study analyzes the direct and indirect effect of optimism on LS in older people among older people with and without restrictions due to illness. The indirect effect was tested using a multiple mediation model of network size, emotional, instrumental and affectionate support, subjective evaluation of social relations and satisfaction with family life for each group while controlling for variables that have been found to have an impact on LS (age, self-rated health and the number of illnesses). The sample comprised 406 community-dwelling older adults (M = 74.88, SD = 6.75) from urban areas in Granada, southern Spain. Health status was modestly related to LS while optimism and social relations variables were positively and strongly associated with LS. Among the proposed mediators network size, tangible support and satisfaction with family life mediated the relationship between optimism and LS in the group of people without restrictions due to illness, while for the participants who reported restrictions due to illness only network size and satisfaction with family life mediated the relation between optimism and LS. Optimism and social resources are important factors that are linked to well-being in old age. Network size, tangible support and satisfaction with family life partially explain the relationship between optimism and LS.