The very last wireless network technology, created to increase the speed and the connections responsiveness, the Fifth-Generation Network (5G) can transmit a great volume of data. It uses wireless broadband connections to support specific end-users and businesses services. It is specifically useful for the Internet of Vehicles (IoV), guaranteeing fast connections and security. The 5G network technology can be used to support Vehicle-to-Everything (V2X) communications and applications on autonomous vehicles. It can enable information exchanges between vehicles and other infrastructures and people. It can also provide a more comfortable and safer environment and accurate traffic knowledge. The traffic flow can be improved, reducing pollution and accident rates. The cellular network can be associated with V2X as a communicating base to offer enhanced road safety and autonomous driving, and also to offer the IoV connections. This survey presents the 5G technology evolution, standards, and infrastructure associated with V2X ecosystem by IoV. In other words, it presents the IoV supported by 5G V2X communications, considering its architecture, applications and also the V2X features and protocols, as well as the modes, the evaluation and the technological support in such combination. The contribution of this paper is a systematized study about the interaction among these three contents: IoV, 5G, and V2X. Eighty four works were selected to present concepts, standards and to identify the ways to overcome challenges. This survey aims to guide the development of new 5G-V2X services and technologies dedicated to vehicle communications, and also to indicate future directions. INDEX TERMS IoV, connected vehicles, 5G networks, V2X communications.