The legislative districts of Negros Occidental are the representations of the province of Negros Occidental in the various national legislatures of the Philippines. The province is currently represented in the lower house of the Congress of the Philippines through its first, second, third, fourth, fifth, and sixth congressional districts.

In 1899, the cities and pueblos of San Carlos, Calatrava, Escalante, Sagay, Cadiz, Manapla, Victorias, and Saravia shall compose the first district. From General Order No. 30, from Office US Military Governor in the Philippine Islands, Manila, P.I. July 22, 1899.^[1]

Negros Occidental was divided into three legislative districts from 1907 to 1972, it was redistricted into six legislative districts in 1986. It was part of the representation of Region VI from 1978 to 1984, and from 1984 to 1986 it elected 7 assemblymen at-large. Until 1986, Bacolod was part of its representation.

• Cities: Escalante (became city 2001), San Carlos
• Municipalities: Calatrava, Salvador Benedicto, Toboso
• Population (2020): 381,716^[2]

• Cities: Cadiz, Sagay (became city 1996)
• Municipality: Manapla
• Population (2020): 362,521^[2]

• Cities: Silay, Talisay (became city 1998), Victorias (became city 1998)
• Municipalities: Enrique B. Magalona, Murcia
• Population (2020): 482,646^[2]

• Cities: Bago, La Carlota
• Municipalities: Pontevedra, Pulupandan, San Enrique, Valladolid
• Population (2020): 406,666^[2]

• City: Himamaylan (became city 2001)
• Municipalities: Binalbagan, Hinigaran, Isabela, La Castellana, Moises Padilla
• Population (2020): 464,026^[2]

Notes

• Cities: Kabankalan (became city 1997), Sipalay (became city 2001)
• Municipalities: Candoni, Cauayan, Hinoba-an, Ilog
• Population (2020): 525,597^[2]

• Legislative district of Bacolod