The miniaturization of satellite systems has compounded the need to protect microelectronic components from damaging radiation. Current approaches to mitigate this damage, such as indiscriminate mass shielding, built‐in redundancies, and radiation hardened electronics, introduce high size, weight, power, and cost penalties that impact the overall performance of the satellite or launch opportunities. Additive manufacturing provides an appealing strategy to deposit radiation shielding only on susceptible components within an electronic assembly. Here, we describe a versatile material platform and process to conformally print customized composite inks at room temperatures directly and selectively onto commercial‐off‐the‐shelf electronics. The suite of inks uses a flexible styrene‐isoprene‐styrene block copolymer binder that can be filled with particles of varying atomic densities for varying radiation shielding capabilities. Additionally, the system readily allows blended composites that contain multiple particle species with varying atomic composition within the same structure. The method can produce graded shielding that offers improved radiation attenuation via exquisite control over both shield geometry and composition. We anticipate this alternative to traditional shielding methods will enable the rapid proliferation of the next generation of compact satellite designs.This article is protected by copyright. All rights reserved