The First Nations community of Neskantaga (also known as Lansdowne House) is located on the west side of the lake.

The name of the lake comes from a region through which the Attawapiskat River flows less than 100 kilometres (62 mi) from its mouth, where it has carved out several clusters of high limestone islands, nicknamed by canoeists the "Birthday Cakes".

[4] Attawapiskat Lake has two outlets, one at its eastern end and the other at the extremity of a bay extending to the northeast.

The streams from these outlets run in a generally easterly direction for about 48 kilometres (30 mi) before merging.

[6] In the early 1990s, the First Nation that lived at Lansdowne House was relocated to the new community of Neskantaga, built on the shores of Attawapiskat Lake's southwestern end.