Jam Island is one of 34 islands surrounding Whole Cake Island as part of the Big Mom Pirates' main territory known as Totto Land. It is run by Charlotte Dacquoise, the Minister of Jam (ャム大臣 Jamu Daijin?). It is the second island of the Charlotte Family siblings' secret route to Whole Cake Island.
Jam Island has rivers of juice flowing through it pouring to the sea, coloring the waters around it. 
Less than 62 years ago, Jam Island became part of the Big Mom Pirates territory also known as "Totto Land", and its appearance was changed to its current look using Charlotte Linlin and Streusen's Devil Fruits (the Soru Soru no Mi and Kuku Kuku no Mi respectively).
Four Emperors Saga
Whole Cake Island Arc
- Jam Island has buildings modeled after glass mason jars, commonly used to store food such as jam.
- One Piece Manga and Anime — Vol. 83 Chapter 829 (p. 3-4) and Episode 788, The Sanji Retrieval Team spot Jam Island before continuing their journey.
- One Piece Magazine Vol.5 (p. 136), Dacquoise's position and island is named.
- One Piece Manga and Anime — Vol. 83 Chapter 828 (p. 10) and Episode 787.
- One Piece Manga and Anime — Vol. 83 Chapter 829 (p. 6) and Episode 788, Pedro explains the reason for the grape-colored sea.
- One Piece Manga and Anime — Vol. 86 Chapter 868 (p. 8-11) and Episode 838, Streusen and Linlin begin their takeover of the archipelago.