Abstract: Ubiquitination is a crucial post-translational modification that is extensively involved in the regulation of protein activity, signal transduction, and the maintenance of genomic stability. As an important member of the deubiquitinating enzyme (DUB) family, ubiquitin-specific protease 11 (USP11) dynamically regulates the stability and function of key tumor proteins by targeting specific substrates for deubiquitination. This, in turn, influences various biological behaviors of tumor cells, including proliferation, apoptosis, migration, invasion, metastasis, and drug resistance, ultimately exhibiting a dual role in either promoting or inhibiting cancer. This article systematically reviewed the relevant research progress on the role of USP11 in tumorigenesis and development and provided an in-depth analysis of the specific mechanisms by which USP11 participates in cellular biological behaviors, aiming to offer a theoretical basis for the future development of small-molecule inhibitors targeting USP11, the formulation of combination drug strategies, and the identification of effective biomarkers.