The genus Coelastrum Nägeli (Sphaeropleales; Scenedesmaceae) is a diverse genus of green algae with potential biotechnical applications. A sound understanding of its phylogeny will be a useful tool for predicting the distribution of traits that may enhance its utility, and may lead to a better understanding of its evolution and ecology. Here we present the plastome of Coelastrum microporum. Our exemplar was isolated from Gull Lake, Michigan and the complete plastome as assembled was 169,961 bp in length. The plastome contained 104 genes of which 68 were protein-coding genes (CDSs), 27 tRNA genes and three rRNA genes. The GC content of the plastome was 31.2%. The maximum likelihood phylogeny suggested that C. microporum was the sister group to a clade of single exemplars of three other genera in the Scenedesmaceae (Tetradesmus, Pectinodesmus and Coelastrella).