Coscinasterias is a cosmopolitan genus of large asteroid sea stars with the ability of somatic fission as a clonal reproductive strategy. During fission, the animals tear themselves apart across their central disc, where the lost body parts are regenerated afterwards. Here, we have sequenced and subsequently analysed the transcriptome of the coelomic epithelium of a clonal Coscinasterias muricata specimen from New Zealand. Out of the total 389,768 raw reads, 11,344 contigs were assembled and grouped into functions. Raw read and assembled contig sequences are available at NCBI (BioSample: SAMN03371637), while the annotated assembly can be accessed through the project transcriptome browser (https://compgen.bio.ub.edu/gbrowse/starfish_transcriptome/). Our data is valuable for future detailed exploration of the coelomic epithelium functions as well as for a better understanding of sea star physiology.