WRKY transcription factors have been demonstrated to influence the anthocyanin biosynthesis in many plant species. However, there is limited knowledge about the structure and function ofWRKYgenes in the major ornamental plant azalea (Rhododendron simsii). In this study, we identified 57RsWRKYgenes in theR. simsiigenome and classified them into three main groups and several subgroups based on their structural and phylogenetic characteristics. Comparative genomic analysis suggestedWRKYgene family has significantly expanded during plant evolution from lower to higher species. Gene duplication analysis indicated that the expansion of theRsWRKYgene family was primarily due to whole-genome duplication (WGD). Additionally, selective pressure analysis (Ka/Ks) suggested that allRsWRKYduplication gene pairs underwent purifying selection. Synteny analysis indicated that 63 and 24 pairs ofRsWRKYgenes were orthologous toArabidopsis thalianaandOryza sativa, respectively. Furthermore, RNA-seq data was used to investigate the expression patterns ofRsWRKYs, revealing that 17 and 9 candidate genes may be associated with anthocyanin synthesis at the bud and full bloom stages, respectively. These findings provide valuable insights into the molecular mechanisms underlying anthocyanin biosynthesis inRhododendronspecies and lay the foundation for future functional studies ofWRKYgenes.