Thompson Beach is a locality in the Australian state of South Australia located on the eastern coastline of Gulf St Vincent about 56 kilometres (35 miles) north of the Adelaide city centre.

[7] Thompson Beach is located within the federal Division of Grey, the state electoral district of Narungga, and the local government area of the Adelaide Plains Council.

[4][1] Thompson Beach is particularly known for its blue swimmer crabs, with the prime season being from October to April.

The beach has an extremely gradual incline, allowing a fisherman to walk several hundred meters out to sea during low tide while the water remains below knee level: this provides a vast area for crabbing.

[9] In recent years, a greater emphasis has been put on sustainable practices to preserve this ecosystem, encouraging a relaxed approach that minimizes harm to the crabs and their habitat.