Radio-frequency (RF) integrated circuit (IC) (RFIC) packages employing a substrate sidewall partial shield for electro-magnetic interference (EMI) shielding. A RFIC package includes an IC die layer that includes a RFIC die(s) mounted on a substrate that includes substrate metallization layers, a substrate core, and substrate antenna layers. The RFIC package includes an EMI shield surrounding the IC die layer and extending down shared sidewalls of the IC die layer and the substrate. The EMI shield extends down the sidewalls of the IC die layer and substrate metallization layers of the substrate to at least the interface between the substrate metallization layers and the substrate core, and without extending adjacent to the sidewall of the substrate antenna layers. In this manner, antenna performance of the antenna module may not be degraded, because extending the EMI shield down sidewalls of the substrate antenna layers can create a resonance cavity in the substrate.