Dodonaea viscosa (Sapindaceae), a Hawaiian local medicinal plant, has been traditionally used to treat rashes and skin diseases. The study aimed to discover and characterize bioactive compounds from D. viscosa flowers extract with antimicrobial and antitumor properties. Thirteen compounds were isolated from the methanol extract of D. viscosa flowers, and their structures were characterized using spectroscopy data, comparing their NMR spectroscopic profiles with previously reported data. Subsequent antibacterial assays revealed that one particular compound, 12, exhibited significant antimicrobial activity against Gram-positive bacteria. Notably, it demonstrated a minimum inhibitory concentration (MIC) of 2 μg/mL, indicating its potent antibacterial potential. In addition to antimicrobial properties, the isolated compounds demonstrated dose-dependent antiproliferative effects in breast cancer cell lines. Notably, inflammatory breast cancer (IBC) cell lines, a highly aggressive subtype, were more sensitive to compound 6, with IC₅₀ values of 4.22 μM (BCX-010), 6.74 μM (SUM190), and 7.73 (SUM149), compared to non-IBC cell line. These findings highlight the dual antibacterial and anticancer potential of compounds from D. viscosa, emphasizing their promise as candidates for therapeutic development.