The design of functional systems with sizes in the nanometer range is a key challenge in fields such as biomedicine, nanotechnology, and engineering. Some of the most promising materials nowadays consist of self-assembling peptides or peptide-polymer hybrid materials because of their versatility and the resulting properties that can be achieved with these structures. Self-assembly of pure amphiphilic peptides or in combination with block copolymers results in a large variety of nanostructures (micelles, nanoparticles (NPs), compartments, planar membranes) each with different characteristics and tunable properties. Here, we describe such novel peptide- or peptide-polymer-based supramolecular nanostructures and emphasize their functionality and various promising applications.