Corals are ecosystem engineers in the deep sea like their tropical shallow-water relatives. Across depth, these ecosystems are threatened by anthropogenic disturbances, including global ocean change and hydrocarbon extraction. While numerous studies focus on how shallow-water corals respond to stressors, there is still little research about the stress responses of deep-sea corals. Here, we analyze the gene expression patterns from a reef-forming deep-sea coral, Lophelia pertusa, exposed to oil and dispersant mixtures under current and projected future temperature and pH conditions. The overall gene expression patterns varied by coral colony, but the dispersant exposure induced the strongest response. A Weighted-Gene Correlation Network Analysis (WGCNA) identified networks of co-expressed genes in response to oil and dispersant exposures, a decrease in pH, and an increase in temperature. Gene ontology (GO) enrichment analysis revealed that L. pertusa likely experienced varying stages of the cellular stress response (CSR) during exposure to oil, dispersant, and a decrease in pH. The dispersant exposure resulted in GO terms related to apoptosis, the immune system, wound healing, and stress-related responses. Alternatively, the coral nubbins exposed to oil exhibited signs of resource reallocation and a reduction in growth to maintain cellular homeostasis. The decrease in seawater pH indicated a less severe stress response than to the dispersant exposure. Our results suggest that distinct stages of the CSR are induced depending on the intensity of stress and bolster the idea that there is an underlying environmental stress response (ESR) shared by all corals in response to a variety of stressors.