This narrative historical review examines the development of internet-based cognitive behavioral therapy (ICBT) in Sweden, describing its progression within both academic and routine care settings. The review encompasses key publications, significant scientific findings, and contextual factors in real-world settings. Over 25 years ago, Sweden emerged as a pioneering force in internet-delivered treatment research for mental health. Since then, Swedish universities, in collaboration with research partners, have produced substantial research demonstrating the efficacy of ICBT across various psychological problems, including social anxiety disorder, panic disorder, generalized anxiety disorder, and depression. Although research conducted in clinical settings has been less frequent than in academic contexts, it has confirmed the effectiveness of therapist-supported ICBT programs for mild-to-moderate mental health problems in routine care. Early on, ICBT was provided as an option for patients at both the primary care level and in specialized clinics, using treatment programs developed by both public and private providers. The development of a national platform for delivering internet-based treatment and the use of procurement in selecting ICBT programs and providers are factors that have shaped the current routine care landscape. However, gaps persist in understanding how to optimize the integration of digital treatment in routine care, warranting further research and the use of specific implementation frameworks and outcomes. This historical perspective on the research and delivery of ICBT in Sweden over two decades offers insights for the international community into the development and broad dissemination of a specific digital mental health intervention within a national context.