This document refers to multi-die micromechanical system (MEMS) packages. In an example, a multi-die MEMS package can include a controller integrated circuit (IC) configured to couple to a circuit board, a MEMS IC mounted to a first side of the controller IC, a through silicon via extending through the controller IC between the first side and a second side of the controller IC, the second side opposite the first side, and wherein the MEMS IC is coupled to the through silicon via.