Nguyễn Khắc Hiếu (阮克孝), pen name Tản Đà (chữ Hán: 傘沱, 19 May 1889 – 7 June 1939) was a Vietnamese poet. A writer in both traditional Sino-Vietnamese literature and European alphabet (“Quốc ngữ”), he was a transitional figure between the turn of the 1890s Confucian scholars such as Tú Xương and Nguyễn Khuyến and the European-influenced "New Poetry" movement of the 1930s.