The authors explore associations between objective and subjective social network characteristics and loneliness in later life, using data from the National Social Life, Health, and Aging Project, a nationally representative sample of individuals ages 57 to 85 in the United States. Hierarchical linear regression was used to examine the associations between measures of objective and subjective social network characteristics and their importance in predicting loneliness across marital status. For the entire sample, as well as the married-cohabitating subsample, objective indicators such as frequency of contact with social network members were negatively associated with feelings of loneliness, net of background characteristics. However, the authors' analysis highlights the contribution of subjective perceptions of social ties, the quality of marriage in later life for those engaged in marital or cohabitating relationships, and the quality of familial ties for the nonmarried older adults. In a married-cohabitating subsample, the subjective perceptions of one's relationship with the partner explained, by itself, 7% of the variance in loneliness, whereas the quality of family ties explained an additional 6% of the variance in loneliness in the nonmarried sample. Based on the present findings, practical implications for social workers are discussed.