| Big Annemessex River | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Maryland |
| Source1 Location: | Kingston, Maryland, United States |
| Mouth Coordinates: | 38.0482°N -75.8735°W |
| Mouth Elevation: | 0feet |
| Basin Size: | 34.6sqmi |
| Tributaries Left: | Hall Creek, Holland Creek |
| Tributaries Right: | Acre Creek, Jones Creek, Coulbourn Creek, Gales Creek, Annemessex Creek |
The Big Annemessex River is a 15.4adj=midNaNadj=mid[1] tributary of the Chesapeake Bay on the Delmarva Peninsula.[2] It rises in Kingston, Somerset County, Maryland, and flows roughly southwest about 6miles in a meandering pattern, then widens into an estuary and continues about 9miles to the bay, near Janes Island State Park. Tributaries include Annemessex Creek, Holland Creek, Hall Creek, Muddy Creek, Colbourn Creek, Jones Creek and Daugherty Creek.
The river is spanned once by River Road, a residential county road far from any population center. The Annemessex Creek upstream, however, is spanned by Maryland Route 413.
There is also a Little Annemessex River; the city of Crisfield rests upon its shores.