BackgroundATP‐binding cassette subfamily G member 1 is mostly known as a transporter for intracellular cholesterol efflux, and a number of studies indicate that ABCG1 also functions actively in tumor initiation and progression. This review aimed to provide an overall review of how ABCG1 acts in tumor progression.MethodA comprehensive searching about ABCG1 and tumor was conducted up to November 2023 using proper keywords through databases including PubMed and Web of Science.ResultOverall, ABCG1 plays a crucial role in the development of multiple tumorigenesis. ABCG1 enhances tumor‐promoting ability through conferring stem‐like properties to cancer cells and mediates chemoresistance in multiple cancers. Additionally, ABCG1 may act as a kinase to phosphorylate downstream molecules and induces tumor growth. In tumor microenvironment, ABCG1 plays a substantial role in immunity response through macrophages to create a tumor‐favoring circumstance.ConclusionHigh expression of ABCG1 is usually associated with poor prognosis, which means ABCG1 may be a potential biomarker for early diagnosis and prognosis of various cancers. ABCG1‐targeted therapy may provide a novel treatment for cancer patients.