The ARID family is a superfamily of 15 members containing a domain that interacts with AT-rich DNA elements. However, the expression and prognostic roles of each ARID in breast cancer are still elusive.We used the TCGA and Kaplan-Meier plotter databases to assess the expression and prognostic values of ARID mRNA levels in breast cancer respectively. In the present study, 6 members were significantly lower in tumor tissues than those in the normal tissues, while 6 members were significantly higher. Further assessment of ARID expression in breast cancer with different molecular subtypes, 3 members were significantly higher in no-luminal molecular subtype than those in the luminal molecular subtype, and 6 members were significantly higher. In regard to prognostic values, high expression of ARID1A, ARID2, ARID3B, ARID4A, ARID5A, ARID5B, JARID1A were associated with favorable outcome, while ARID4B and JARID1B were correlated to a worse outcome. We further analyzed the prognostic value of ARID in different intrinsic subtypes and clinicopathological features of breast cancer. We found many meaningful ARID family biomarkers in breast cancer. The relevant results will expound the role of ARID in breast cancer and may further provide new insight to explore the ARID-targeting reagents for treating breast cancer patients.