Thermal energy storage (TES) systems play a very important part in addressing the energy crisis. Therefore, numerous researchers are striving to improve the efficiency of TES tanks. The TES technology has the potential to reach new heights when the biological behavior of nature is incorporated into the design of TES tanks. By mimicking the branched vein pattern observed in plants and animals, the heat transfer fluid (HTF) tube of a TES tank can enhance the heat transfer surface area, hence improving its thermal efficiency without the need to add other enhancements of heat transfer methods. Accordingly, in this study, a unique additive-manufacturing-based bio-inspired TES tank was designed, developed, and tested. A customized testing setup was used to assess the bio-inspired TES tank’s thermal performance. A comparison was made between the bio-inspired TES tank and a conventional shell-and-tube TES tank. The latent TES system’s thermal performance was significantly enhanced by the biomimetic approach for the design of a TES tank, even before the optimization of its design. The results showed that, compared to the shell-and-tube TES tank, the bio-inspired TES tank had a higher discharging rate and needed 52% less time to release the stored heat.