Unmanned agricultural ground vehicles (UAGVs) represent substantial potential with their ability to optimize crop yields and increase sustainability, making them a high priority with many academic and corporate institutions. These systems need to be safe and robust while operating in suboptimal conditions compared to other autonomous systems. The variability encountered in the field, such as ground conditions, weather, and the sheer size of the operations highlight just a few of the challenges they face. Reliable communication networks will help to achieve safe and reliable operations in these conditions. This chapter discusses advances in communication systems in agricultural robotics. The need for communication systems is first addressed. An introduction to wireless communication then follows with communication layers, network topology, and communication technologies all discussed. Sections are then included on both person-to-machine (cellular networks and Multiple-Input and Multiple-Output broadband radio antenna networks) and machine-to-machine (Wi-Fi, Bluetooth, ZigBee, IPv6 over Low Power Wireless Personal Area Networks, and Radio Frequency Identification) communication. The chapter concludes with a discussion on security issues.