The Taj-ul-Masajid (Arabic: تَاجُ ٱلْمَسَاجِد‎, romanized: Tāj-ul-Masājid, lit. 'Crown of Mosques') or Tāj-ul-Masjid (تَاجُ ٱلْمَسْجِد‎), is a mosque situated in Bhopal, Madhya Pradesh, India. It is the largest mosque in India and one of the largest mosques in the world.
The construction of the Taj-ul-Masajid was started by Nawab Shah Jahan Begum of Bhopal, in the newly-built walled suburb of Shahjahanabad. The exact year when construction was started is unclear; Sharma estimates it to be 1871. After Shah Jahan Begum died in 1901, the mosque continued to be built by her daughter Sultan Jahan Begum, till the end of her lifetime. The structure was planned in the midst of three water bodies, namely: Munshi Hussain Talab; Noor Mahal Talab; and Motia Talab.

The mosque was not completed due to a lack of funds, and construction did not resume until 1971. The entrance was renovated with motifs from 13th century Syrian mosques donated by the Emir of Kuwait in memory of his late wife.

During the COVID-19 pandemic, the mosque was used as a vaccination center.

The Taj-ul-Masajid largely takes inspiration from Mughal architecture. The mosque has a pink facade topped by two 18-storey high octagonal minarets with marble domes, an impressive main hallway with attractive pillars, and marble flooring resembling the likes of Jama Masjid in Delhi and the Badshahi Mosque of Lahore. It has a courtyard with a large ablution tank in the centre. It has a double-storeyed gateway with four recessed archways and nine cusped multifold openings in the main prayer hall. The massive pillars in the hall hold 27 ceilings through squinted arches of which 16 ceilings are decorated with ornate petalled designs.[citation needed]

The mosque also features a zenana (women's gallery), rare given that prayer from home was the norm for women at the time of the mosque's construction.