Chackbay is located along the northern edge of Lafourche Parish at . Its northern boundary is the border with
St. James Parish. Settlement follows the major roads through the community, which follow higher ground. Large areas away from the roads are wetland and mainly undeveloped.
Louisiana Highway 20 runs through the western part of the CDP, leading south to
Thibodaux, the
parish seat, and northeast to
Vacherie.
Highway 304 runs west and southwest from Highway 20 to
Bayou Lafourche west of Thibodaux, and
Highway 307 runs east to
Kraemer. Unincorporated communities within the Chackbay CDP are, from west to east, Choupique, Chegby, and Chackbay. According to the
United States Census Bureau, the Chackbay CDP has a total area of , all of it recorded as land. ==Demographics==