Officers say Connell Schultz was last seen in Preston at around 9am on Tuesday.
He is described as being 5ft 11 inches tall of slim build and was last seen wearing a navy blue Northface tracksuit top and bottoms and black Berghaus coat.
As well as Preston he also has links to Blackpool.
A police spokesman said: “If you have seen Connell or know where he is, please get in touch.
“Connell, if you are reading this, please let someone know you are okay.”
Anyone with information should contact police on 01772 209112 or 101 quoting log number LC-20190417-0006