A system for and a method of providing an integrated communications and broadcasting service are provided. This system includes a transmitter and a receiver. The transmitter RF-multiplexes a CATV broadcasting signal and a satellite broadcasting signal, converts the RF-multiplexed broadcasting signal into an RF-multiplexed broadcasting optical signal having a predetermined wavelength, multiplexes the broadcasting optical signal with an Internet data signal, and transmits an integrated communications and broadcasting optical signal via a predetermined optical fiber. The receiver receives the integrated communications and broadcasting optical signal from the transmitter, demultiplexes the received signal according to a wavelength band to separate the received signal into the broadcasting optical signal and the Internet data signal, separates the broadcasting optical signal into the CATV broadcasting signal and the satellite broadcasting signal using the difference between wavelength bands of the CATV broadcasting signal and the satellite broadcasting signal, and transports the separated signals to appropriate terminals.