Negative and repetitive self-oriented thinking (rumination) is associated with lower well-being and health. The social context of rumination remains underexplored and mostly centers on marital relationships. To embrace the diversity of older adult relationships, this study includes a range of different relationships (e.g., spouses, siblings, friends, etc.) and examines the role of rumination by close others on individual well-being during the coronavirus disease 2019 pandemic. Using daily diary data from 140 Canadian older adults (M = 72.21 years, standard deviation SD = 5.39, range: 63-87 years, 47% women, 71% university educated) and a close other of their choice (M = 59.95 years, SD = 16.54, range: 18-83 years, 78% women, 81% university educated), this project builds on past research examining daily life rumination dynamics from a dyadic perspective. For 10 days, both dyad members reported their daily rumination and affect quality in the evening. Multilevel models replicate past work showing that individual rumination was associated with higher negative affect (within-person: b = 0.27, p < .001, between-person: b = 0.57, p < .001) and lower positive affect (within-person: b = -0.18, p < .001, between-person: b = -0.29, p < .001). Importantly, we additionally observed that partner rumination was associated with higher negative affect (b = 0.03, p = .038) and lower positive affect (b = -0.04, p = .023), highlighting the social context of rumination. Findings illustrate the significance of rumination for the self and others and underline the merit of taking a dyadic perspective on what is typically viewed as an individual-level phenomenon.