Protein kinases represent a highly promising drug target, with over 80 drugs that target about two dozen different protein kinases have been approved by the US FDA, particularly in cancer treatment. Over the past decades, the unique structural characteristics of the thienopyrimidine ring system provide an adaptive platform for designing potent anticancer agents, especially various kinase inhibitors, which has attracted widespread attention. Some of these thienopyrimidines as anticancer kinase inhibitors have already been marketed or are currently undergoing clinical/preclinical studies for the treatment of cancers, such as Olmutinib, Pictilisib, SNS-314, PF-03758309, and Fimepinostat, highlighting the substantial advantages of the thienopyrimidine scaffold in the discovery of anticancer agents. This article reviews the discovery, activity, and structure-activity relationships of antitumor kinase inhibitors based on the thienopyrimidine scaffold, and partially discusses the binding modes between thienopyrimidine derivatives and their kinase targets. By elucidating the application of thienopyrimidine derivatives as anticancer kinase inhibitors, this review aims to provide new perspectives for the development of more effective and novel kinase inhibitors.