Hemlock is an unincorporated community in Richland Township, Saginaw County in the U.S. state of Michigan. It is also a census-designated place (CDP) for statistical purposes, but without any legal status as an incorporated municipality. The population of the CDP was 1,585 at the 2000 census. The area included in the CDP is in the south central portion of Richland Township. The Hemlock post office, with ZIP code 48626, serves nearly all of Richland Township, as well as portions of Fremont Township to the south, small areas of Thomas and Swan Creek townships to the southeast, and part of Ingersoll Township to the north in Midland County.
The community was first settled in 1865. A Post Office was established in 1869 with the name "Hemlock City". This was shortened to Hemlock in 1895.
According to the United States Census Bureau, the CDP has a total area of 2.5 square miles (6.6 km²), none of which is covered by water.