Mr Smith was last seen at 12:55 on Friday, 31 January, walking in the direction of Battisford.
He is described as white, 6ft 1in tall, with a slim build, very long brown hair, and a brown beard. When he was last seen, he was wearing a blue/grey checkered shirt with jeans and boots.
Police and family members are concerned for his welfare and are appealing for anyone with information about his whereabouts to come forward.
Members of the public can report sightings to Suffolk Police by calling 101 or using the force's online reporting system, quoting CAD 131 of 31 January.
