The 65-year-old was last seen at approximately 8.50am this morning (May 23) at his home on Oaktree Drive.
Police in Hampshire and his family are extremely concerned for his welfare and officers are carrying out extensive enquiries to locate him.
Simon is described as being white, around 5ft 9 inches tall, with shaved hair and of stocky build.
He was last seen wearing a polo shirt, chino shorts, black Asics trainers and had reading glasses on his head.
If you see Simon or have any information on his whereabouts, please call us on 101 quoting the reference 44220203888.
Always call 999 in an emergency.