The exceptional mechanical properties of the byssus-the fibrous holdfast of mussels that provides underwater adhesion-have potential applications in medicine and technology. The catechol-Fe3+-catechol interaction underlies the unique properties of mussel byssus and has emerged as a tool for developing functional hybrid materials such as pH-responsive, self-healing gels. Herein, the construction of functional alginate (Alg) film on a solid substrate inspired by mussel byssus is reported. The approach consists of spin-coating-assisted deposition of Alg catechols onto a solid substrate and their subsequent crosslinking via catechol-Fe3+-catechol interactions. This yields robust and multilayered Alg films that are resistant to protein adsorption and suppress bacterial adhesion. This method can be used to create antibacterial films for coating implanted medical devices.