| Lassul Bay | |
| Type: | Bay |
| Basin Countries: | Papua New Guinea |
| Pushpin Map: | Papua New Guinea |
| Pushpin Map Alt: | Location of Lassul Bay |
| Coordinates: | -4.2125°N 151.7242°W |
Lassul Bay is a bay of East New Britain Province, Papua New Guinea, opening into the Bismarck Sea. It is located in the north-western part of New Britain, to the west of Ataliklikun Bay on the Gazelle Peninsula. The communities around Lassul Bay are incorporated into the twenty-one wards of the Lassul-Baining Local-Level Government (LLG) including the settlement of Lassul.[1] The land around the shoreline is swampy and the area has a history of plantation cultivation.[1] The area was invaded in February 1942 by the Japanese during the Battle of Rabaul.[2]