Breast cancer (BC) remains a leading cause of cancer-related mortality, largely due to its aggressive proliferation and metastatic potential. Long non-coding RNAs (lncRNAs) have emerged as key regulators in tumor development and progression. This study explored the functional role and mechanism of Lnc-PRSS23-AS1 in BC. We assessed Lnc-PRSS23-AS1 expression and localization using fluorescence in situ hybridization, qRT-PCR, and Western blotting in BC tissues and cell lines. Binding interactions between Lnc-PRSS23-AS1, miR-3176, and Y-box binding protein 1 (YBX1) were validated through dual-luciferase reporter assays, RNA pulldown, and RNA immunoprecipitation. Lnc-PRSS23-AS1 was significantly upregulated in BC and predominantly localized in the cytoplasm. Silencing Lnc-PRSS23-AS1 or overexpressing miR-3176 suppressed BC cell proliferation, migration, and invasion in vitro and in vivo. Conversely, miR-3176 inhibition or YBX1 overexpression reversed these effects. Mechanistically, Lnc-PRSS23-AS1 promoted YBX1 protein expression by acting as a molecular sponge for miR-3176. These findings highlight the Lnc-PRSS23-AS1/miR-3176/YBX1 axis as a driver of BC progression and suggest Lnc-PRSS23-AS1 as a potential therapeutic target for breast cancer treatment.