According to the United States Census Bureau, the CDP has a total area of 8.7 square miles (23 km2), of which, 8.7 square miles (23 km2) of it is land and 0.04 square miles (0.10 km2) of it (0.34%) is water.
While Grand Bay is unincorporated, the area is served by the Grand Bay Water Works Board for water service and an active volunteer fire department for fire protection. The Mobile County Sheriff's Department maintains a satellite office in Grand Bay as well. Grand Bay Water Works also provides limited sewer service for Breitling Elementary School and the business district around the Interstate 10 exchange. The Mobile County Commission, a three-member elected panel, provides all other services including road and street repair.
Grand Bay is located within District 3 of the Mobile County Commission. The current commissioner is Jerry Carl (R). In the Alabama Legislature, Grand Bay is located within House District 105. The current representative is David Sessions(R), a native of Grand Bay. In the State Senate, Grand Bay is located within District 34. This District is currently represented by Rusty Glover.
In the US House, Grand Bay, and all of Mobile County is located within the 1st Congressional District.
A July 4 tradition since 1973, the current version of the Grand Bay Watermelon Festival offers tourists and locals an opportunity to sample locally grown watermelon while enjoying local music, arts & crafts, and informative displays from area merchants and service providers.
The annual celebration has a long and storied history, having begun during the earliest years of the 20th Century. As the community and surrounding area changed during World War II, the annual celebration was discontinued. It was revived in 1973 by the Grand Bay Junior Chamber of Commerce. Currently, it is sponsored by the Grand Bay Independent Odd Fellows #73. It is currently held at the Festival Park and local baseball park just north of U.S. Highway 90 on the west side of Grand Bay. The website for the Grand Bay Watermelon Festival is: www.grandbaywatermelonfestival.org. The website for the Grand Bay Independent Order of Odd Fellows is: www.grandbayioof.org.