Background: Colorectal cancer (CRC) remains a prevalent and lethal malignancy, ranking as the second leading cause of cancer-related deaths globally. Elucidating its molecular mechanisms and identifying diagnostic/prognostic biomarkers are critical for improving survival outcomes. Methods: Survival analysis was employed to unveil the prognostic value of the TIMP1 in CRC patients. Leveraging the TIMER2.0 and TISIDB databases, we systematically analyzed correlations between TIMP1 expression and immune cell infiltration, tumor-infiltrating lymphocytes (TILs), and immune checkpoint gene levels across multiple cancer types. The association between TIMP1 expression and the tumor immune microenvironment in CRC was evaluated using the ESTIMATE algorithm. Differentially expressed genes were identified via the Limma package, followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses to elucidate TIMP1-mediated oncogenic mechanisms. Protein-protein interactions of TIMP1-binding partners were explored using the STRING database, and Venn diagram analysis combined with Spearman correlation analysis was performed to investigate relationships between TIMP1 expression and co-expressed genes. TIMP1 mRNA levels were validated by Quantitative Real-Time PCR (RT-qPCR). Results: Integrated bioinformatics and experimental data confirmed significantly elevated TIMP1 expression in CRC, which correlated with poor overall survival and disease-specific survival. Notable differences in immune cell infiltration (macrophages, neutrophils, B cells, CD8⁺ T cells, mast cells, monocytes, CD4⁺ T cells, and dendritic cells) were observed between TIMP1-high and TIMP1-low expression groups. TIMP1 expression was significantly associated with TILs, immune checkpoint genes, and immunomodulatory chemokines. Twelve TIMP1-interacting Differentially expressed genes (DEGs) were prioritized: FN1, COL5A1, PRG4, MMP1, MMP2, MMP3, MMP7, MMP8, MMP9, MMP11, MMP13, and MMP14. Conclusion: TIMP1 emerges as a prognostic biomarker and therapeutic target in CRC, with functional implications in modulating the tumor immune microenvironment.