The Jama Masjid Shamsi is a major mosque built in the historic center of Budaun, Uttar Pradesh, India.

The masjid was built by Iltutmish, the ruler of Delhi Sultanate at that time. This masjid echoes Persian and Afghan architecture. It has three gates: the main gate, facing Shakeel Road, is made up of red marble and stands 100 feet tall. The second gate is in Farshori Tola and the third one in Sotha. It has a central dome surrounded by two more domes, and 5 other domes too. The floor is made from white marble (SangeMarMar). It has a "Hauz" (pond) and three "WuzuKhana" (Washroom and sitting Room) on its premises. Two sides of mosque are occupied by residential blocks: the Jama Masjid Quarters.

The mosque is built on an elevated area called Sotha Mohalla, and is the highest structure in the town of Budaun.

This masjid is the third oldest existing and seventh largest mosque of the country after Delhi's Jama Masjid, having a standard capacity of 23500. The built up part of the mosque is larger than any other mosque of the country. Before the expansion of Delhi's Jama Masjid, it was the largest and most famous mosque of the country. The central dome of the mosque is the largest dome of any mosque in the country.

It is also a Monument of National Importance and a National Heritage Site.

In October 2022 Hindu organizations claimed the site as one where a Hindu temple served as a foundation for the mosque. They propose demolishing the mosque in order to reclaim the site as a Hindu temple.