Grannis is a city in Polk County, Arkansas, United States. The population was 575 at the 2000 census.
Near Grannis is the Boggs Springs Youth Encampment of the American Baptist Association, a retreat of Missionary Baptist churches.
Grannis is located at 34°14′20″N 94°19′42″W / 34.23889°N 94.32833°W / 34.23889; -94.32833 (34.238884, -94.328404).