Oz was an American television drama series created and written by Tom Fontana. It was the first one-hour dramatic television series to be produced by HBO. It aired for six seasons between 1997 and 2003.

Oz is the nickname for the Oswald State Correctional Facility, a maximum-security prison of undisclosed location. Many of the plot arcs are set in Emerald City ("Em City"), an experimental unit of the prison in which the unit manager attempts to emphasize rehabilitation and learning responsibility during incarceration. Emerald City is a controlled environment where there are a limited number of members of each racial and social group.