Abstract Hybrid heterostructures are pivotal in the advanced broadband detection technology. The emergence of 2D semimetals has expanded the range of materials in heterostructures beyond conventional narrow‐gap materials for room‐temperature broadband detection applications due to their extraordinary optical and electrical properties. This review outlines the cutting‐edge and latest advancements in broadband photodetectors (PDs) engineered from heterostructures that synergistically combine 2D semimetals with several different dimensional materials. It begins with a fundamental investigation, offering an in‐depth explanation of the essential material properties and a summary of synthesis methodologies. Then, the discussion advances to provide an analytical overview of the categorization, underlying photodetection mechanism, and figures‐of‐merit of these advanced PDs. Subsequently, the narrative shifts to a comprehensive analysis of heterogeneous integrated devices. The review further highlights the diverse optoelectronic applications of broadband PDs, spanning image sensing, optical communication, position‐sensitive detection, integrated sensing and computing, spintronics, and computational spectroscopy are thoroughly highlighted. Finally, the review concludes by addressing the challenges and opportunities in advancing 2D semimetal materials for photodetection.