Hayden Frances Dunham (born June 16, 1988) is a performance artist, designer, singer, songwriter and DJ. They grew up in Austin, Texas and attended the Gallatin School of Individualized Study at NYU.

They are best known for their work as QT (an initialism for Quinn Thomas) a music project founded in 2014, in collaboration with English producer A. G. Cook, and Scottish producer Sophie. QT is a pop singer, portrayed by Dunham and sung by Harriet Pittard, who promotes and is the living embodiment of the semi-fictitious DrinkQT energy drink. They released the single "Hey QT" in 2014.

Dunham began operating under the pseudonym Hyd (/hīd/) in 2020, releasing their debut single "No Shadow" in September 2021. A four-track EP was released November 5. Hyd's debut album Clearing was released on November 11, 2022, via PC Music.