Poor sleep quality is a risk factor for many adverse health outcomes and has become a widespread and serious public health problem, especially among older adults. This study aimed to explore the association between dysphagia, loneliness, and their interaction with sleep quality among older Chinese adults living in nursing homes. This cross-sectional study used multistage cluster random sampling to select 56 nursing homes in Hunan Province, China. Data on sociodemographic characteristics, health-related status, lifestyle, and behavioral and social psychological factors were collected. The Pittsburgh Sleep Quality Index was used to evaluate sleep quality. The 30 mL Water Swallowing Test and Eating Assessment Tool-10 items were used to screen for dysphagia, and the 14th item of the Center for Epidemiologic Studies Depression Scale was used to measure loneliness. Binary logistic regression models were used to analyze the relationship between poor sleep quality, dysphagia, and loneliness. The interaction between these variables was evaluated using multiplicative and additive interaction models. This study included 3,356 older adults aged 60 and above. The mean Pittsburgh Sleep Quality Index score was 6.31 ± 3.11, and the incidence of poor sleep quality was 30.8%. A total of 642 (19.1%) older adults had dysphagia, and 1,358 (40.5%) experienced loneliness. After adjusting for all covariates, dysphagia and loneliness were associated with an increased risk of poor sleep quality. The interaction analysis demonstrated that the risk of poor sleep quality among older adults with dysphagia and loneliness was 3.476 times higher than that in those without dysphagia and loneliness. Dysphagia and loneliness had an additive interaction effect on poor sleep quality in older adults living in nursing homes. Poor sleep quality can be effectively prevented by focusing on older adults in nursing homes experiencing dysphagia, loneliness, or both and implementing targeted health interventions.