| Official Name: | Marial Bai |
| Pushpin Map: | South Sudan |
| Pushpin Label Position: | top |
| Pushpin Map Caption: | Location in South Sudan |
| Subdivision Type: | Country |
| Subdivision Type1: | Region |
| Subdivision Name1: | Bahr el Ghazal |
| Subdivision Type2: | State |
| Subdivision Name2: | Northern Bahr el Ghazal |
| Subdivision Type3: | County |
| Subdivision Name3: | Aweil West County |
| Unit Pref: | Imperial |
| Population As Of: | 2005 |
| Population Blank1 Title: | Ethnicities |
| Population Blank2 Title: | Religions |
| Timezone: | CAT |
| Utc Offset: | +2 |
| Coordinates: | 9.1022°N 26.8478°W |
Marial Bai is a village in Northern Bahr el Ghazal state, South Sudan.
Marial Bai lies between the Magadhik River and Chel or Kuru River, which converge to form the Lol River.It is the real-life hometown of Valentino Achak Deng, the protagonist of the Dave Eggers book, What is the What.[1] Devastated during Sudan's second civil war, Marial Bai now benefits from the efforts of the Valentino Achak Deng Foundation, which has constructed a new Marial Bai Secondary School.[2] [3]