As with most Spanish cities, night starts late at Seville. The most happening neighbourhoods for nightlife are Alfalfa, Alameda de Hercules and Calle Betis.
Alfalfa attracts young university crowd. Pérez Galdó in Alfalfa has many bars catering to students. Alameda de Hercules attracts those into alternative scene. Calle Betis along the water front in Triana and running parallel to the Guadalquivir River is Seville’s most famous hangout with bars every 200 metres. Central Seville is not particularly known for its nightlife. However, Flaherty on Calle Alemánes, located right next to the Cathedral, attracts expats and tourists.
For the tourists, the best nightlife option is watching a flamenco performance. If you plan well, you can catch a flamenco performance for free in Seville.
Alternately, you can either go to one of the touristy tablaos that offer professional performances, usually with tapas and drinks or a more informal alternative at Tirana or at one of the many Penas like Peña Torres Macarena at Torrijiano, outside the old centre.