Circular RNA (circRNA), as a newly discovered non-coding RNA with important regulatory potential, is closely related to the occurrence and progression of various tumors. This study aimed to investigate has_circ_0000069 expression in breast cancer and its influence on cellular activities. Using real-time quantitative polymerase chain reaction, has_circ_0000069 levels were measured in 137 pairs of tissue specimens, as well as cancer cell lines. The cellular activities of cell lines were determined by cell counting kit-8 (CCK-8) and Transwell assays. The potential targeting miRNAs were predicted and verified using an online database and dual-luciferase reporter assay. Has_circ_0000069 was highly expressed in breast cancer tissues and cells. The expression of has_circ_0000069 was associated with the five-year overall survival of patients. After silencing has_circ_0000069 in breast cancer cells, its expression reduced, and the ability of cell proliferation, migration, and invasion decreased. MiR-432 was verified as a targeting miRNA of has_circ_0000069. Has_circ_0000069 expression increased in breast cancer and was negatively related to patient’s prognosis. Has_circ_0000069 may facilitate breast cancer tumor progression by sponging miR-432. These findings revealed that has_circ_0000069 may be a biomarker for predicting prognosis and a therapeutic target for treating patients with breast cancer.