Mark Britton, 48, was reported missing from the Woodthopre area this morning.
He wasÂ last seen leaving Queen Mary Road at around 10.25am but hasn't been seen or heard from since.
He is known to frequent the Heeley area of the city and also the Peace Gardens.
Officers said they were concerned for Mark's welfare and wanted to hear from anyone who has seen or spoken to him since this morning.
He is thought to be wearing blue tracksuit bottoms with a white stripe on, a dark blue hooded coat, a green woolly hat and black trainers.
Anyone with any information should call police on 101, quoting incident number 273 of October 8.