Cyclin-dependent kinase 1 (CDK1) plays a significant role in certain malignancies. However, it remains unclear whether CDK1 plays a role in esophageal squamous cell carcinoma (ESCC). The aim of this study was to analyze the expression and clinical value of CDK1 in ESCC. CDK1 protein in 151 ESCC tissues and 138 normal esophageal tissues was detected by immunohistochemistry. RNA-seq of eight pairs of ESCC and adjacent esophageal specimens was performed to evaluate the levels of CDK1 mRNA. Microarray and external RNA-seq data from 664 cases of ESCC and 1733 cases of control tissues were used to verify the difference in CDK1 expression between the two groups. A comprehensive analysis of all data was performed to evaluate the difference in CDK1 between ESCC tissues and control tissues. Further, functional enrichment analyses were performed based on differentially expressed genes (DEGs) of ESCC and coexpressed genes (CEGs) of CDK1. In addition, a lncRNA-miRNA-CDK1 network was constructed. The expression of CDK1 protein was obviously increased in ESCC tissues (3.540 AE 2.923 vs. 1.040 AE 1.632, P < 0.001). RNA-seq indicated that the mRNA level of CDK1 was also highly expressed in ESCC tissues (5.261 AE 0.703 vs. 2.229 AE 1.161, P < 0.0001). Comprehensive analysis revealed consistent up-regulation of CDK1 (SMD = 1.41; 95% CI 1.00-1.83). Further, functional enrichment analyses revealed that the functions of these genes were mainly concentrated in the cell cycle. A triple regulatory network of PVT1-hsa-miR-145-5p/hsa-miR-30c-5p-CDK1 was constructed using in silico analysis. In summary, overexpression of CDK1 is closely related to ESCC tumorigenesis.Esophageal cancer is one of the most common malignant tumors in the world and is the seventh highest cause of cancer-related death [1]. There are approximately 19,260 new cases and 15,530 deaths each year [1]. Esophageal squamous cell carcinoma (ESCC) is the main subtype of esophageal cancer, accounting for 90% of all esophageal cancers [2]. Thus far, the main treatment method for ESCC is a combined treatment of radiotherapy, chemotherapy, and surgery [3]. The emergence of drug resistance in molecular targeted Abbreviations CDKs, cyclin-dependent kinases; CDK1, cyclin-dependent kinase 1; CEGs, co-expressed genes; DEGs, differentially expressed genes; ESCC, esophageal squamous cell carcinoma.