<p><span style=color: rgba(23 43 77 1)>This Special Issue reprint provides an overview of object detection in images and videos with a focus on addressing the resource constraints of lightweight vision sensors. Object detection has long been a key research area in computer vision. It is now gaining increasing attention from both academia and industry driven by the rapid advancement of deep neural networks (DNNs) and high-resolution vision sensors. While DNNs have achieved remarkable success in recent years they are becoming increasingly complex with deeper network structures and larger training datasets. This growing complexity poses a challenge for deploying computationally and data-intensive DNNs on resource-limited vision sensors particularly for real-time object detection.</span></p>