One of the current biotechnological applications is nanofiber applications made from algae using the electrospinning technique. Nanofibers containing poly‐caprolactone (PCL) extracted from the brown seaweed Hijiki (Sargassum fusiforme) were prepared using electrospinning technique. Water extraction was performed to preserve the integrity of Hijiki components, ensuring their efficacy in subsequent electrospinning and characterization. The morphology and chemical composition of the nanofibers were characterized using field emission scanning electron microscopy (FE‐SEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT‐IR) analyses. Hijiki was found to combine well with electrospun biocompatible polymers and effectively provide the common properties of these materials. The cytotoxicity of algae‐doped PCL nanofibers was examined in vitro using liver cancer and liver healthy cell lines (HepG2 and The‐2). Among hepatic tumor cell lines, the HepG2 cell line has been preferred due to its wide range of scientific applications. Although the nanofibers caused a 28% decrease in liver cancer cell lines viability (HepG2), the decrease in healthy liver cell viability (The‐2) was 12%. Algae‐doped PCL nanofiber applied to bacteria showed antibacterial effect. Based on the findings, Hijiki macroalgae nanofibers show great promise for tissue regeneration and band‐aid applications in the medical industry.