In this study, Hypericum perforatum L. has been used for dyeing woolen fabrics and improving antibacterial properties. Tin chloride, iron II sulfate, alum and copper II sulfate mordant materials were used to dye wool with Hypericum perforatum L. Dyeings also performed without using mordant materials. H. perforatum was extracted prior to dyeing. Fourier transform infrared (FTIR), inductively coupled plasma-mass spectrometry (ICP-MS), antibacterial activity, and fastness testing of the dyed fabric samples were performed. Scanning electron microscope (SEM) images of the dyed samples were also examined. It was determined that H. perforatum L. can be used for dyeing woolen fabrics while imparting antibacterial properties.