Biomimetic tendon-reinforced" (BTR) composite structures feature improved properties including a very high strength-to-weight ratio. The basic structure includes plurality of parallel, spaced-apart stuffer members, each with an upper end and a lower end, and a plurality of fiber elements, each having one point connected to the upper end of a stuffer member and another point connected to the lower end of a stuffer member such that the elements form criss-crossing joints between the stuffer members. The stuffer members and fiber elements may optionally be embedded in a matrix material such as an epoxy resin. The fiber elements are preferably carbon fibers, though other materials, including natural or synthetic fibers or metal wires may be used. The stuffer members may be rods, tubes, or spheres, and may be constructed of metal, ceramic or plastic. The stuffer members are preferably spaced apart at equal distances. If the members are tubes, the fiber elements may be dressed through the tubes. Alternatively, the fiber elements may tied to the ends of the stuffer members and/or to each other at the joints. Both linear and planar structures are disclosed.