Ala'i Darwaza is the southern gateway of the Quwwat-ul-Islam Mosque in Qutb complex, Mehrauli, Delhi, India. Built by Sultan Alauddin Khalji in 1311 and made of red sandstone, it is a square domed gatehouse with arched entrances and houses a single chamber.

Alauddin Khalji, born Ali Gurshasp, was a ruler from the Khalji dynasty that ruled the Delhi Sultanate in the Indian subcontinent. Alauddin instituted a number of significant administrative changes, related to revenues, price controls, and society. He also successfully fended off several Mongol invasions of India.