Water-soluble triblock copolymers (PEO-PPO-PEO) are utilized to provide thermoreversible micellar templates for three-dimensional nanoparticle arrays. The triblock forms a cubic micellar structure with typical dimensions of tens of nanometers. The temperature-dependent amphiphilic nature of the block copolymers provides increased structure control and allows the use of pre-made silica and gold nanoparticles as well as globular proteins. Using rheology and small-angle neutron scattering (SANS), we characterize the influence of the nanoparticles on the local particle structure and on the macroscopic mechanical properties. We are able to incorporate significant quantities of nanoparticles into the block copolymer gel without destroying the ordered structure. Contrast matching SANS demonstrates that some level of the template structure is transferred to the nanoparticles. This study demonstrates the feasibility and potential of using this simple approach to generate novel nanoparticles-polymer composites.