Tamper-respondent assemblies and methods of fabrication are provided which include a multi-layer stack having multiple discrete component layers stacked and electrically connected together via a plurality of electrical contacts in between the component layers. Further, the tamper-respondent assembly includes a tamper-respondent electronic circuit structure embedded within the multi-layer stack. The tamper-respondent electronic circuit structure includes at least one tamper-respondent sensor embedded, at least in part, within at least one component layer of the multiple discrete component layers of the multi-layer stack. The tamper-respondent electronic circuit structure defines a secure volume within the multi-layer stack. For instance, the tamper-respondent electronic circuit structure may be fully embedded within the multi-layer stack, with monitor circuitry of the tamper-respondent electronic circuit structure residing within the secure volume within the multi-layer stack.