Brigadier Ivan Simson OBE (1890–1971) was the Chief Engineer in Malaya from August 1941 until its surrender to the Japanese in 1942. Simson was tasked with improving the defenses in Singapore in the face of possible attack by the Japanese, although Simson's defensive recommendations were largely rejected by his commander, Arthur Percival, as being bad for moral. Previously he was Deputy Chief Engineer Scottish Command.