ERECTAs are receptor-like kinases that regulate plant biomass and stress resistance. In this study, the wheat (Triticum aestivum) TaERECTA gene was used as a probe to identify the SbERECTA family genes (SbERs) in the sorghum (Sorghum bicolor) genome, analyse their subcellular localisation and characterise their expression. Results showed that the two SbER members, SbER10 with three copies (SbER10_X1, SbER10_X2, and SbER10_X3) and SbER4 with two copies (SbER4_X1 and SbER4_X2), were found on chromosomes 10 and 4 of sorghum, respectively. SbER10 had the highest expression level in the pedicel tissue and showed a remarkable response under treatment with abscisic acid, brassinolide, gibberellin and indole-3-acetic acid. SbER10_X1, functioning on the cell membrane and chloroplast, exhibited abundant transcript in only a few sorghum varieties that are grown in mountainous areas and receive strong light, heat, and water supply. Expression of SbER10_X1 was significantly and positively correlated with plant biomass of 32 sorghum germplasm resources. These results indicate that SbER10 genes have an important regulatory role in sorghum growth, and increasing SbER10 transcription level offers a potential strategic target for breeding or biotechnological approaches to enhance sorghum biomass and environmental adaptability.