Martin, who is from the Swallownest area of Rotherham, was last seen on 25 February 2021, although he has been spoken to on the phone since then.
Martin is around 5ft 11 ins tall with light brown hair. He was last seen wearing a black puffer jacket, black joggers and black trainers.
Officers involved in the search for Martin are becoming increasingly concerned for his welfare.
Do you know where Martin is? Have you seen him recently? Do you have information that may help?
Please call 101 quoting incident 899 of 25 February 2021.