Oum Er-Rbia River

{{Infobox river

| name = Oum Er-Rbia

| image = File:Oum Er-Rbia River.svg

| image_caption = Location of the Oum Er-Rbia River in Morocco

| length = {{convert|555|km|abbr=on}}

| source1_elevation =

| source1_location = Middle Atlas

| mouth_location = Atlantic Ocean

| discharge1_avg = {{convert|105|m3/s|abbr=on}}

| basin_size =

| subdivision_type1 = Country

| subdivision_name1 = Morocco

}}

Oum Er-Rbia ({{langx|ar|أم الربيع|translit=the mother of spring}}) is a large, long and high-throughput river in central Morocco.

The river is {{Convert|555|km}} long.{{Cite book|title=Natural Wonders of the World|publisher=Reader's Digest Association, Inc|year=1980|isbn=0-89577-087-3|editor-last=Scheffel|editor-first=Richard L.|location=United States of America|pages=284|editor-last2=Wernet|editor-first2=Susan J.}} With an average water throughput of 105 m³/s, Oum Er-Rbia is the second-largest river in Morocco after the Sebou River. It originates in the Middle Atlas and passes through the city of Khénifra, arriving at its mouth at the Atlantic Ocean at the port of Azemmour, located on its left bank. Oum Er-Rbia has six dams, the most important of which is Al Massira Dam. Its most important tributaries are the El-Abid River, the Tessaoute River, and the Lakhdar River.

According to scholars, the original Berber common name of the river is Wansifen and was only changed recently, circa 16th or 17th century, and a nearby village called Oum Rabia might have influenced this change.{{cite book|script-title=ar:التشوف إلى رجال التصوف, circa 1220 AD|pages=309, 340|author=Ibn al-Zayyat al-Tadili|author-link=Ibn al-Zayyat al-Tadili|edition=Ahmed Toufiq|language=ar}}

Oum Er-Rbia is fed by a large number of groundwater springs. The area near its headwaters is called "The Forty Springs" as a result, although that is a poetic term rather than an exact count.