The Masjid-i-Jahan Numa (Hindi: मस्जिद-ए-जहां नुमा, Urdu: مسجد جھان نمہ), commonly known as Jama Masjid जामिया/जामा मस्जिद of Delhi, is the principal mosque of Old Delhi in India.
Commissioned by the Mughal Emperor Shah Jahan and completed in the year 1656 AD, it is one of the largest and best-known mosques in India.
It is also at the beginning of a very busy and popular street/center in Old Delhi, Chandni Chowk.

Masjid-i-Jahan Numa means “the mosque commanding a view of the world”, and the name Jama Masjid is a reference to the weekly congregation observed on Friday (the yaum al-jum`a) at the mosque.
The courtyard of the mosque can hold up to twenty-five thousand worshippers.
The mosque also houses several relics in a closet in the north gate, including a copy of the Qur’an written on deer skin.

Shah Jahan built several important mosques in Delhi, Agra, Ajmer and Lahore.
The Jama Masjid’s floorplan is very similar to the Jama Masjid at Agra, but the Jama Masjid is the bigger and more imposing of the two.
Its majesty is further enhanced because of the high ground that he selected for building this mosque.
The architecture and design of the Badshahi Masjid of Lahore built by Shah Jahan’s son Aurangzeb in 1673 is closely related to the Jama Masjid in Delhi.