The wireless edge caching is considered as a promising technique to cope with rapid increase in mobile traffic demand. The fundamental idea of edge caching is to offload the data traffic to local cache memories by dealing with content requests with the pre-fetched contents on network edge nodes. The wireless edge caching consists of two main phases: content placement and content delivery. Since the strategies for these two phases are highly dependent on which devices are capable of caching in the network, the characteristics and types of achievable caching gains appear to vary with the location of cached data. The cached data at the transmitter side can be utilized to reduce the traffic load on backhaul and the latency, while the cached data at the receiver side can be utilized to improve the network resource efficiency and the quality of experience (QoE) of the end-users. This chapter introduces the state-of-the-art wireless edge caching techniques for transmitters and receivers of ultra dense networks and offers a design guideline on reaping the promising gain of wireless edge caching.