Aziz Mahmud Hudayi (1541–1628), (b. Şereflikoçhisar, d. Üsküdar), is amongst the most famous sufi ermiş's (Muslim saint) of the Ottoman Empire. He was a mystic, poet, composer, author, statesman and Hanafi Maturidi Islamic scholar.
Born in Şereflikoçhisar, he completed his studies in a medrese in Istanbul. He was the Sheikh of Sultan Ahmed I who constructed the famous Blue Mosque and especially gained the respect of Sultan Murad III. He read the first Friday prayer in this mosque on its opening. He is a descendant of Junayd of Baghdad, and being descendant of Husayn ibn 'Ali, he is a sayyid. He is therefore of Hashemite ancestry. 
He founded the sufi order Jelveti. He also served as qadi in Edirne, Egypt, Sham (Syria), and Bursa. He was a murid and khalifah of Üftade Hazretleri. He wrote about thirty works, seven of which are in Turkish. His disciple was Mustafa Gaibi, a prominent sufi from Ottoman Bosnia.
His supplication, "Those who visit us when we are alive, and those who visit our grave after our death and read the Fatiha when passing by our tomb are ours. May those who love us not drown at sea, may they not suffer poverty in their old age, may they not pass away without saving their faith," has prompted many sailors of the Ottoman Empire to visit his grave before going out to sea.
He died in Üsküdar, Istanbul and is buried next to his mosque.
Four Patron Saints of the Bosphorus
He along with Yahya Efendi, Telli Baba, and Joshua are considered to be the Four Patron Saints of the Bosphorus.