Background: In Korea, liver cancer is the fifth most frequently diagnosed cancer and has the second highest cancer mortality rate. Despite recent advances in systemic therapy, patients with Hepatocellular carcinoma (HCC) continue to have poor prognoses as many are diagnosed at an advanced disease stage. To better understand the current treatment landscape and contribute to improved patient outcomes, the LINK (Liver Cancer in Korea) research network was established as a longitudinal real-world HCC database with annual data refresh. The aim was to provide current and up-to-date real-world insights into HCC patient characteristics, treatment patterns, and outcomes. Methods: LINK’s data sources are the electronic medical records of three leading academic hospitals (Asan Medical Center, Samsung Medical Center, Severance Hospital). Extracted data are standardized using a study-specific common data model to ensure comparability across hospitals. Adult patients with primary diagnosis of HCC (ICD-10: C22.0) in 2015-2020 were included and followed until death, loss to follow-up, or June 2021, whichever occurred first. Patients without valid treatment records or morphology codes or with other primary cancer diagnosis were excluded. Data on key patient and clinical characteristics, treatments, such as systemic anti-cancer therapy (SACT) regimens, and real-world outcomes were collected. Rule-based algorithms were developed to define initial treatments and lines of therapy in palliative SACT. Results: Of 25,480 HCC patients identified, 10,298 (40%) met eligibility criteria and were included in the analysis. The median age was 60 years and 19% were female. There were 74% of patients classified as Child-Pugh (CP) class A, 16% as B, 1% as C, and 9% with unknown CP at diagnosis. For albumin-bilirubin (ALBI) grade at diagnosis, 49% of patients were classified as grade 1, 45% as 2, 5% as 3, and 1% unknown. Loco-regional therapy was the most common initial treatment, with 54% and 13% of patients receiving transarterial therapy and local ablation therapy, respectively. A total of 628 patients (6%) undergone liver transplantation regardless of preceding treatments and 15% of patients were initially treated with hepatectomy. Only 2% received radiation therapy (RT) or RT in combination with cytotoxic chemotherapy as initial treatment. Among 3,026 patients who received SACT either as an initial (10%) or subsequent treatment, 67%, 20%, and 13% received 1 line, 2 lines, and 3 lines of therapy. The most common first-line SACT was sorafenib, followed by lenvatinib. Conclusions: The LINK database can serve as a multi-center research platform to facilitate fast and reliable real-world evidence generation for HCC patients. Future updates and subgroup analyses of interest can further evaluate the impact of new therapies and changes to HCC treatment guidelines in Korea.