| Oum Lahyad | |
| Native Name: | ام لحياظ |
| Settlement Type: | Commune and village |
| Pushpin Label Position: | bottom |
| Pushpin Mapsize: | 300 |
| Pushpin Map Caption: | Location in Mauritania |
| Subdivision Type: | Country |
| Subdivision Name: |  Mauritania |
| Subdivision Type1: | Region |
| Subdivision Name1: | Hodh El Gharbi |
| Subdivision Type2: | Department |
| Subdivision Name2: | Ayoun el Atrous |
| Leader Title: | Mayor |
| Unit Pref: | Imperial |
| Area Total Km2: | 5886 |
| Population As Of: | 2013 |
| Population Total: | 10997[1] |
| Population Density Km2: | 1.868 |
| Timezone: | GMT |
| Utc Offset: | ±00:00 |
| Native Name Lang: | ar |
Oum Lahyad is a village and rural commune located in the department of Ayoun el Atrous, in the region of Hodh El Gharbi in the country of Mauritania.
As of the census completed on 25th March 2013, Oum Lahyad has a population of 10,997. This is a 54% increase from the 7,139 figured reported on the previous and only other recorded census in November 2000.[1]