Semiconductor device assemblies with molded support substrates and associated methods are disclosed herein. In one embodiment, a semiconductor device assembly includes a support substrate formed from a molded material, a first semiconductor die at least partially embedded within the support substrate, a plurality of interconnects extending at least partially through the molded material, a second semiconductor die coupled to the support substrate, and a third semiconductor die coupled to the support substrate. The assembly can also include a redistribution network formed on a first and/or second side of the support substrate, and a plurality of conductive contacts electrically coupled to at least one of the first, second and third semiconductor dies.