Omdurman (Arabic: أم درمان, romanized: Umm Durmān) is a major city in Sudan. It is the second most populous city in the country, located in the State of Khartoum. Omdurman lies on the west bank of the River Nile, opposite and northwest of the capital city of Khartoum. It is on the Nile river and acts as an important road hub, with the Nile boosting transportation even further.

The name Omdurman (Umm Durmān) literally translates as "Mother of Durmān", but who she was or might have been is unknown.

After the siege of Khartoum, followed by the building there of the tomb of the Mahdi after his death from typhus, the city grew rapidly. However, in the Battle of Omdurman in 1898 (which actually took place in the nearby village of Kerreri), Lord Kitchener decisively defeated the Mahdist forces. The following year British forces defeated Abdallahi ibn Muhammad, the Khalifa, as the Battle of Umm Diwaykarat; ensuring British control over the Sudan.

In September 1898, the British army of twenty thousand well drilled men equipped with the latest arms, Maxim guns and Martini-Henry rifles under the command of General Horatio Herbert Kitchener invaded Sudan. In the battle of Omdurman, the British Army faced Sudanese defenders consisting of over 52,000 poorly armed desert tribesmen dervishes; in the space of five hours the battle was over. The Sudanese defenders suffered many casualties, with at least 10,000 killed. By contrast there were fewer than four hundred casualties on the British side with forty-eight British soldiers losing their lives. Then, General Kitchener proceeded to order the desecration of the Mahdi's tomb and in the words of Winston Churchill, "carried off the Mahdi's head in a kerosene can as a trophy".

Kitchener restored Khartoum as the capital and, from 1899 until 1956 Sudan was jointly governed by Great Britain and Egypt. Although most of the city was destroyed in the battle, the Mahdi's tomb was restored and refurbished.

On 10 May 2008, the Darfur rebel group of the Justice and Equality Movement moved into the city where they engaged in heavy fighting with Sudanese government forces. Their goal was to topple Omar Hassan al-Bashir's government.

During the Sudanese civil war, the Battle of Omdurman broke out.

• Ombadda

Omdurman features a hot arid climate, with only the summer months seeing noticeable precipitation. The city averages a little over 155 millimetres (6.1 in) of precipitation per year. Based on annual mean temperatures, the city is one of the hottest major cities in the world. Temperatures routinely exceed 40 °C (104 °F) in mid-summer.

Its average annual high temperature is 37.1 °C (99 °F), with six months of the year seeing an average monthly high temperature of at least 38 °C (100 °F). Furthermore, throughout the year, none of its monthly average high temperatures falls below 30 °C (86 °F). During the months of January and February, while daytime temperatures are generally very warm, nights are relatively cool, with average low temperatures just above 15 °C (59 °F).

Year	Population
1909 (Census)	42,779
1941	116,196
1956	113,600
1973	299,399
1983	526,284
1993	1,271,403
2007 Estimate	2,127,802
2008	2,395,159
2010	2,577,780

Public universities are:

• Karary University
• Omdurman Islamic University
• University of the Holy Quran and Islamic Sciences

Private universities are:

• Ahfad University for Women
• Omdurman Ahlia University
• University of Science and Technology - Omdurman

Khartoum Airport serves Omdurman.

According to Sudanese officials, in 2005 a new airport facility had been proposed 30 miles (50 km) south of Omdurman. Arguably speaking to be within the non-defined boundaries of Omdurman, the project was estimated to be completed by 2012 with an estimated budget of $530 million. Construction began in 2019 but as of 2021 had been suspended.

• Al-Nilin Mosque
• Bant (Omdurman)
• Khalifa House Museum

• Media related to Omdurman at Wikimedia Commons
• "Omdurman" . Encyclopædia Britannica. Vol. 20 (11th ed.). 1911. p. 101.