| Lock and Dam No. 6 | |
| Location Map: | Wisconsin |
| Dam Crosses: | Upper Mississippi River |
| Res Name: | Pool 6 |
| Location: | Trempealeau County, Wisconsin / Winona County, Minnesota, United States. Near Trempealeau, Wisconsin. |
| Operator: | U.S. Army Corps of Engineers, St. Paul District |
| Dam Length: | 893feet(movable portion) |
| Opening: | June |
| Res Capacity Total: | 180000acre feet |
| Res Catchment: | 60030mi2 |
| Coordinates: | 43.9997°N -91.4383°W |
Lock and Dam No. 6 is a lock and dam located near Trempealeau, Wisconsin on the Upper Mississippi River near river mile 714.1. It was constructed and placed in operation in June 1936. The last major rehabilitation was from 1989 to 1999. The dam consists of 893feet long concrete structure with five roller gates and 10 tainter gates. Its earth embankment is 2600feetlong and the concrete overflow spillway is 1000feet long. The lock is 110feet wide by 600feet long. The lock and dam are owned and operated by the St. Paul District of the United States Army Corps of Engineers-Mississippi Valley Division.