Abstract Triply periodic minimal surfaces (TPMS)‐based lattice structures exhibit improved mechanical and energy absorption properties compared to other lattices. Fused filament fabrication is the preferred approach for fabricating these structures and majority of the existing TPMS structures are manufactured using a single polymer. This study presents composite lattice structures that are reinforced with a second material. TPMS lattice structures are designed using MSLattice and modeled into cubical, cylindrical, bar, and dogbone geometries with relative density levels of 25%, 50%, and 75%. The structures are 3D printed with micro carbon fiber‐embedded nylon as the base matrix and fiberglass as the reinforcement. The structures are then characterized for mechanical properties and energy absorption as a function of density. The results show that the 25% relative density fiberglass‐reinforced structures exhibited similar or better properties compared to the 75% density structures without reinforcement. The mass normalized maximum force withstood by the 25% density‐reinforced cylinder was 1340 N/g compared to 1219 N/g for the 75% density non‐reinforced cylinder, clearly demonstrating the benefits of adding fiberglass. The 25% density cylindrical samples' energy absorption capacity increased on an average by 24.8% with the addition of fiberglass. The 25% density bar and dogbone samples' exhibited the highest improvement with the addition of fiberglass with an increase in stress capacity of 64.6% and 113%, respectively. These findings suggest that these lightweight composite TPMS structures can be a promising candidate for energy absorption applications such as the crumple zones in automobiles. Highlights Gyroid structure modeled with 25%, 50% and 75% density in different geometries. Structures 3D printed with onyx fiber and reinforced with fiberglass. Reinforced cylindrical samples' energy absorption capacity increased by 24.8%. Bar and dogbone samples' maximum stress capacity doubled with reinforcement. Composite TPMS structures are good candidate for energy absorption application.