Greeley was elected to council in the city in western Newfoundland in 2001, and then ran unsuccessfully for mayor in 2005.
The former police officer became mayor in a byelection in 2007.
Greeley says it's the right time to step away and spend time with his family.
Greeley's announcement leaves Coun. Donna Francis as the only declared candidate for the mayor's job.
The next municipal election is on Sept. 24.