Aims The purpose of this study was to isolate, identify and characterize an antifungal compound from Lactobacillus plantarum KCC‐10 from forage silage with potential beneficial properties. Methods and Results The 16S rRNA gene‐based phylogenetic affiliation was determined using bioinformatic tools and identified as Lactobacillus sp. KCC‐10 with 100% sequence similarity to L. plantarum. The antifungal substances were extracted with ethyl acetate from spent medium in which Lactobacillus sp. KCC‐10 was cultivated. Antifungal activity was assessed using the broth microdilution technique. The compounds were obtained by eluting the crude extract with various concentrations of solvents followed by chromatographic purification. Based on the infrared, 13C nuclear magnetic resonance (NMR) and 1H NMR spectral data, the compound was identified as a phenolic‐related antibiotic. The minimum inhibitory concentration of the compound against Aspergillus clavatus, A. oryzae, Botrytis elliptica and Scytalidium vaccinii was 2·5 mg ml−1 and that against A. fumigatus, A. niger and S. fusca was 5·0 mg ml−1, respectively. In addition, Lactobacillus sp. KCC‐10 was highly sensitive towards oxgall (0·3%) but grew well in the presence of sodium taurocholate (0·3%). An antimicrobial susceptibility pattern was an intrinsic feature of this strain; thus, consumption does not represent a health risk to humans or animals. Conclusion Novel L. plantarum KCC‐10 with antifungal and potential probiotic properties was characterized for use in animal food. Significance and Impact of the Study This study revealed that L. plantarum KCC‐10 exhibited good antifungal activity similar to that of probiotic Lactobacillus strains.