Efficient and affordable multidisciplinary thermal management technologies are becoming increasingly important in emerging aviation, power, and electronics cooling applications. High performance compact thermal devices are needed for existing and emerging aerospace systems, which include commercial / military, hybrid-electric, urban air mobility and high-speed air vehicles, among others. Advances in additive manufacturing (AM), materials, and design processes play a critical role in development of next-generation AM-enabled heat exchanger technology. This paper reports recent Boeing-led breakthrough advances in thin-wall (150–175 microns) metallic AM and its use in conformal heat exchangers and cold plates for aircraft engine precooler and electronic cooling applications, respectively. A model based engineering (MBE) approach is used in developing highly efficient AM heat exchanger designs. Their performance benefits are validated using a complimentary numerical simulation and experimental performance measurement method. The measured heat exchanger effectiveness and pressure drop in AM-produced brick-shaped and conformal heat exchangers are in good agreement with model predictions, within ∼5% and 20%, respectively. An overview of steps required for achieving technical maturity and production readiness of metal AM heat exchanger and cold plate technology, along with an envisioned roadmap for adoption of this technology in aviation platforms, is presented.