Photovoltaic-thermal (PV/T) collectors have gained a lot of attention in recent years due to their substantial advantages as compared to ST or PV systems alone and even to other non-solar technologies. However, PV/Ts are still not as popular in industry or construction and they are not even known to major players implementing solar energy installations. In this article, a general presentation of PV/Ts and a review of their applications are given. First, different heat extraction media (e.g., air, water, bi-fluid, etc.) and hybrid design configurations of hybrid PV/T collectors are addressed. Next, the main applications of PV/T collectors are discussed in order to highlight their feasibility and usefulness and to raise awareness for adoption in the industry and buildings sector. Applications include desalination, air-conditioning, drying, trigeneration, etc. This paper should be considered as a reference form of PV/Ts to extract key points for future research and development as well as for other applications.