Background: There is limited data about the anti-breast cancer activity of noni fruit ethanolic extract. Topical route is gaining interest as an alternative route for breast cancer treatment. Objectives: The aims of this study were to investigate the effect of noni fruit extract on cytotoxicity and cell migration suppression in Michigan Cancer Foundation-7 (MCF-7) human breast cancer cells and to develop topical microemulsions (MEs). Materials and Methods: The noni fruit ethanolic extract was prepared. Rutin content, a marker, in the extract was analyzed, and the antioxidant activity of the extract was determined. Cytotoxicity and cell migration suppression, indicating anti-breast cancer activity, were also assessed in MCF-7 cells by SRB assay and wound-healing assay. The MEs were developed by titration method. The developed noni MEs were evaluated regarding their physical appearance, viscosity, and pH before and after stability test. Results: Results showed that the rutin content in the noni extract was 4.02 ± 0.34 mg/g. The extract possessed antioxidant activity with inhibitory concentration (IC50) of 1.03 ± 0.01 mg/ml. It also showed cytotoxicity with IC50 values of 158.4 ± 12.5 μg/ml and cell migration suppression on MCF-7 cells with significant effect at 100 μg/ml. Eight ME systems were selected to incorporate the extract. Conclusion: Noni extract had potential anti-breast cancer activity. The ME, named noni ME-3, consisting of 0.7% w/w noni extract, 56% w/w olive oil, 20% w/w polysorbate 80, 20% w/w sorbitan oleate, and 4% w/w water phase, was shown to be the most attractive noni ME for the topical treatment of breast cancer.