Background: The red gorgonian, Paramuricea clavata, is a structural anthozoan with a key ecological role in rocky benthic and biodiversity-rich communities in the Mediterranean and Eastern Atlantic. This species is submitted to strong defaunation due to direct human activities and habitat destruction. In addition, shallow populations of P. clavata in the North-Western Mediterranean are severely affected by thermal stress mortalities linked to climate change. These mass mortality events (MMEs), which were observed over thousands of kilometers of coastal areas, differentially impacted (i.e. different level of tissue necrosis) individuals and populations of P. clavata. The eco-evolutionary processes and genetic factors involved in these differential responses remain to be characterized. To fill this gap, we sequenced assembled and annotated the genome of P. clavata. The leverage of genomic resources opens new perspectives for the red gorgonian conservation, and also enables functional studies linking variation with adaptation to climate change. Findings: A red gorgonian sample was sequenced with short and long read technologies, producing 169.98 Gb of Illumina paired-end and 3.55 Gb of Oxford Nanopore technologies (ONT) reads. This data allowed us to obtain a de novo hybrid assembly accounting for 712.4 Mb and 107,682 scaffolds. The contig and scaffold N50 are 15.85 Kb and 17.01 Kb, respectively. Despite of the low contiguity of the assembly, the gene completeness was shown to be relatively high, including 86% of the 978 metazoan genes contained in the metazoa_odb9 database. In fact, a total of 76,508 protein-coding genes and 85,763 transcripts have been annotated in the red gorgonian genome. Conclusions: The assembly presented here is one of the few octocoral genomes currently available. This is undoubtedly a valuable resource for characterizing the genetic bases of the differential responses to thermal stress. The identification of thermo-resistant individuals can be extremely useful for active restoration actions. Overall, the red gorgonian genome will help to understand various aspects of its evolutionary ecology and elaborate appropriate conservation plans to overcome the threats of global change.