Murjan Mosque (Arabic: جامع مرجان) is a historic mosque on al-Rashid Street located near the Shorja marketplace and the Abboud Building in Baghdad, Iraq. The walled mosque is significant for housing tombs of prominent Islamic scholars, including Nu'man al-Alusi and also for housing a madrasa. Today, it is considered an important ancient landmark in Baghdad.

There used to be a Madrasa known as Madrasa Murjania, which was founded by Amin al-Din Murjan by the funding of the Jalairid Sultan, Shaykh Uways Jalayir, in 1356. He had also built the Khan Murjan which is located nearby the mosque. The madrasa had taught the four Sunni maddhabs and was sustained by the supplies from Baghdad. Later the hospital that overlooked the Tigris was established for the students of science. The hospital was equipped with a café as well. After the death of Murjan in 1353, he was buried in the madrasa and the dome was erected on top of his tomb.

During James Silk Buckingham's visit to Baghdad in 1816, he visited the Murjan Mosque going back from visiting al-Khulafa Mosque's remains and noted it's inscriptions, entrance and brickwork. He noted that the mosque:

"Has some remains of equally old and very rich Arabesque work, on its surface. The body of the mosque itself is modern, and its interior presents nothing remarkable, but its door of entrance is very fine. This is formed by a lofty arch of the pointed form, bordered on each side by a succession of rich bands, exquisitely sculptured, going up its sides, and meeting at the top, nearly in the form of the arch itself."

When al-Rashid Street was opened after the independence of the Kingdom of Iraq, engineers have suggested removing the mosque because it impedes the straightening of the street, but King Faisal I rejected the idea in favor of preserving the mosque, this decision was also backed by British archeologist and writer Gertrude Bell who also recognized its important heritage. Although this controversy resurfaced during the expansion of al-Rashid Street in 1946 where it was suggested that parts of the mosque must be cut. Although not much was demolished had it been for the many scholars of Baghdad that stood up against the idea which led to its postponement for a while.

Arshad al-Omari, mayor of the capital, held a press conference in its hall saying:

"I am surprised by this intense interest in an antique mosque that has been ruined, and I am ready to build in its place after its destruction a larger and more luxurious mosque. So why this insistence and adherence to it?"

This got him the praise of Baghdadi Newspapers but despite that, parts of the Mosque and the Madrasa were demolished along with the archaeological dome that contained the shrine of Amin al-Din Murjan in favor of al-Rashid Street. The mosque was rebuilt along with its chapel on the other side of the mosque according to its original layout under the supervision of government departments. A renovation of the mosque was conducted in 1973 by the Ministry of Endowment and Religious Affairs.

The Madrasa had a large library, a gift from the scholar Nu'man al-Alusi, who made it an endowment for the students of knowledge in the school. This library, which includes many manuscripts of rare Salafi books, was transferred to the Public Endowments Library, was transferred to the Public Endowments Library, located in Bab Al-Moatham, which was later burned down during the US Invasion of Iraq.

The mosque has an area of 1,500 square metres (16,000 sq ft) and can accommodate 1,200 worshipers. The prayer room is topped by one main dome and two small domes, and the mosque is enclosed by a wall. As for the shape of the building of the current mosque, its construction was established in another wing of the madrasa, where it was safe from the hand of demolition, and three domes were raised over it, the largest of which is the middle dome, in which the dome of the fleeting mosque largely imitated the madrasa’s library. After 2003, the mosque's infrastructure became more chaotic with random basements and ceilings being built around it. Sellers have also left behind rubbish. Dirt and waste have also become common in the mosque due to neglect.

In 2023, Iraqis flocked to Social Media platforms to express their anger and shock after the circulation of pictures showcasing the historic mosque in a state of neglect. Pictures showcased how the mosque was turned into a waste dump, especially with its gate which showcased a large amount of rubbish. Another picture showed the spread of waste in the vicinity of the gate of the Murjan Mosque, and the stagnant water and dirt covered the entrance and the outer courtyards in it. Activists warned of the danger of the mosque's gate collapsing due to the leakage of stale water into the foundations of the gate. The scene sparked a wave of anger among bloggers and activists about the government's continued neglect of archaeological and historical monuments, and their failure to subject them to the supervision of the Ministry of Culture and Tourism or to conduct periodic maintenance of those monuments that date back hundreds of years. It was seen as a clear intention to obliterate Baghdad's historical identity and harm its antiquities and some suspected it was an intentional neglect of the mosque.

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  The mosque during World War I

• Islam in Iraq
• List of mosques in Baghdad
• List of mosques in Iraq