Ceramidases (CDases) are vital sphingolipid enzymes involved in organismal growth and development. They have been reported as key mediators of thermal stress response. However, whether and how CDase responds to heat stress in insects remain unclear. Herein, we identified two CDase genes,C. lividipennisalkaline ceramidase (ClAC) and neutral ceramidase (ClNC), by searching the transcriptome and genome databases of the mirid bug,Cyrtorhinus lividipennis, an important natural predator of planthoppers. Quantitative PCR (qPCR) analysis showed that bothClNCandClACwere highly expressed in nymphs than in adults.ClACwas especially highly expressed in the head, thorax, and legs, whileClNCwas widely expressed in the tested organs. Only theClACtranscription was significantly affected by heat stress. Knocking downClACincreased theC. lividipennisnymph survival rate under heat stress. The transcriptome and lipidomics data showed that the RNA interference-mediated suppression ofClACsignificantly upregulated the transcription level ofcatalase(CAT) and the content of long-chain base ceramides, including C16-, C18-, C24-, and C31- ceramides. InC. lividipennisnymphs,ClACplayed an important role in heat stress response, and the upregulation of nymph survival rate might be caused by variation in the ceramide levels and transcriptional changes inCDasedownstream genes. This study improves our understanding of the physiological functions of insect CDase under heat stress and provides valuable insights into the nature enemy application.