This document describes apparatuses and techniques for radar-based contextual sensing. In some aspects, a radar sensor of a device is activated to obtain radar data for a space of interest. Three-dimensional (3D) radar features are extracted from the radar data and positional data is received from sensors. Based on the positional data, spatial relation of the 3D radar features is determined to generate a set of 3D landmarks for the space. This set of 3D landmarks is then compared with known 3D context models to identify a 3D context model that matches the 3D landmarks. Based on a matching 3D context model, a context for the space is retrieved and used to configure contextual settings of the device. By so doing, contextual settings of the device be dynamically configured to address changes in context or for different device environments.