Syed Abul Hassan Bin Usman Bin Ali Al-Hajweri, also known as Shaikh Ali Hajweri, Data Ganj Bakhsh, or Data Sahib, was a scholar of Islam and a Sufi saint. His most famous work is Kashf al Mahjub ("Unveiling the Veiled"), which was the first Persian language treatise on Sufism. His mausoleum, popularly known as Data Durbar, is located in Lahore, Pakistan.