MicroRNA-128 (miR-128) has been found to be dysregulated and might function as a tumour suppressor in various cancers, including ovarian cancer. However, the underlying mechanism of miR-128 in ovarian cancer has not been fully understood. The miR-128 and homeobox B8 (HOXB8) levels in clinical samples and cultured cell lines were measured using qRT-PCR and/or Western blot analysis. Cell proliferation was assessed using Cell Counting Kit-8 assay. Cell apoptosis was determined using flow cytometry. The association between miR-128 and HOXB8 was confirmed using dual-luciferase reporter assay. Results showed that decreased miR-128 expression and increased HOXB8 expression were observed in ovarian cancer tissues and cell lines. Transfection with miR-128 mimics suppressed the cell proliferation and enhanced paclitaxel sensitivity in ovarian cancer cell lines. miR-128 directly targeted HOXB8 in ovarian cancer cell lines. Knockdown of HOXB8 abolished the effects of miR-128 inhibitor on ovarian cancer cell proliferation and paclitaxel sensitivity. Summarily, miR-128 displayed a tumour suppressor role in ovarian cancer via targeting HOXB8. It is supposed that miR-128 might be effective for targeting therapy for ovarian cancer.