The body was found in the water in Brierley Hill this morning, near Meeting Lane.
Mr Smith, from Brierley Hill, was last seen on December 3. He had left home to visit family but never returned.
Specialist officers had carried out searches of the canal last week in an effort to find the missing man.
West Midlands Police spokeswoman Sharn Braich said: "Officers searching for missing man Simon Smith have this morning found a body in Brierley Hill.
"The body is yet to be formally identified but is believed to be of the 50-year-old.
"The death is not being treated as suspicious and Simon’s family are being supported by specialist officers."