Hans Graf (born 15 February 1949 in Marchtrenk) is an Austrian conductor.

As a child, Graf learned the violin and the piano. He studied at the Musikhochschule in Graz, Austria, and graduated with diplomas in piano and conducting. He also participated in conducting master classes with Franco Ferrara, Sergiu Celibidache, and Arvīds Jansons. He received a state scholarship at the Leningrad Conservatory with Jansons. For the 1975/1976 season Graf was music director of the Iraqi National Symphony Orchestra in Baghdad. After winning the Karl Böhm conductor's competition in 1979, he made his debut at the Vienna State Opera in 1981 with Stravinsky's Petrouchka. He then worked at major opera houses, including Munich, Paris, Florence, Venice, and Rome. Since 1995, he has conducted most major American orchestras, including the Boston Symphony, Cleveland Orchestra, New York Philharmonic and Philadelphia Orchestra.

From 1984 to 1994 Graf was music director of the Mozarteum Orchestra of Salzburg, where he recorded the complete symphonies and other works by Mozart. From 1994 to 1996, he held the position of music director of the Basque National Orchestra, then from 1995 to 2003, of the Calgary Philharmonic Orchestra and from 1998 to 2004 of the Orchestre National Bordeaux Aquitaine, France, where he was nominated member of the Legion of Honour in 2002.

Graf first conducted the Houston Symphony in 2000, and became its music director in 2001. He made his Carnegie Hall conducting debut with the Houston Symphony in 2006. At the conclusion of his Houston tenure in 2013, Graf took the title of Conductor Laureate. He has been an artist-in-residence at the Shepherd School of Music, Rice University. On 2 December 2012 Graf was honoured by the Bruckner Society of America with the Kilenyi Medal of Honor for his performances of the Bruckner's Symphonies 3-4 and 6-9, including the sketches to Finale of the 9th, as well as the Mass No. 2 and the Te Deum.

From 2013 to 2015, Graf was professor of orchestral conducting at Mozarteum University Salzburg. In 2018, he won a Grammy award for his recording of Alban Berg's Wozzeck with Anne Schwanewilms, Roman Trekel and the Houston Symphony. This recording had received an ECHO Klassik award in 2017.

Graf has performed at the summer festivals of Tanglewood, Aspen (both 2017), and Vail (2018).

Graf first appeared with the Singapore Symphony Orchestra in 2015, and returned for a further guest engagement in 2018. In July 2019, the Singapore Symphony Orchestra announced his appointment as its new chief conductor, effective with the 2020-21 season.

In private life, Graf is known as a wine connoisseur. He and his wife, Margarita, have a daughter, Anna.