The fruit of Morus alba L. is rich in bioactive compounds with antioxidant and anti-inflammatory properties; however, the biological effects of its fermented extract have not been fully elucidated. This study investigated the effects of fermentation on the antioxidant and anti-inflammatory activities of mulberry fruit extract (ME). Mulberry fruit was fermented using Lactiplantibacillus plantarum (LP), Lacticaseibacillus casei (LC), and Bifidobacterium bifidum (BB), and the resulting fermented extract (MFE) was compared with non-fermented extract. Cell viability was evaluated by MTT assay in LPS-stimulated RAW 264.7 macrophages, and neither ME nor MFE exhibited cytotoxicity. Antioxidant activity was assessed using the DPPH radical scavenging assay, in which MFE showed higher antioxidant capacity than ME. To evaluate anti-inflammatory activity, nitric oxide (NO) production was measured in LPS-stimulated RAW 264.7 cells. MFE significantly and dose-dependently suppressed NO production compared with ME. These results indicate that fermentation enhances the antioxidant and anti-inflammatory activities of mulberry fruit extract and suggests its potential as a value-added functional plant resource.