The 4th International Symposium for Industrial Control System & SCADA Cyber Security Research (ICS-CSR) brings together researchers with an interest in the security of industrial control systems in light of their increasing exposure to cyber-space. ICS-CSR is a research conference aimed at high-quality academic research in the cyber security of industrial control system from the hardware, system and human-factor perspectives. The papers in this proceedings range from defence-in-depth concepts for ICS and ICS security scanners, runtime monitoring, firewall performance for industrial applications and forensic readiness for SCADA/ICS incident response. This year, ICS-CSR also has an emphasis on smart grid security topics