Disclosed herein are an apparatus and method for transmitting and receiving a 4-layer layered-division multiplexing (LDM) signal. An apparatus for transmitting a 4-layer layered-division multiplexing signal includes a layered-division multiplexing modulation unit for generating a 3-layer layered-division multiplexing signal by performing layered-division multiplexing modulation on three layer signals and generating a 4-layer layered-division multiplexing signal by inserting a Pseudo-random Noise (PN) sequence into the 3-layer layered-division multiplexing signal, a pilot insertion unit for inserting a pilot into the 4-layer layered-division multiplexing signal, and a transmission unit for transmitting the 4-layer layered-division multiplexing signal.