Cebuano and Hiligaynon are the main dialects generally spoken in the households of Negros Oriental. Cebuano is spoken by 969,192 individuals (94.75%) and Hiligaynon or Ilonggo is generally spoken by 49,101 (4.80%) idividuals mostly in areas around Basay, Bayawan, Sta. Catalina, Canlaon City and some areas in Mabinay.
At least 67 dialects or mother tongues are known to be spoken in the different parts of the province. Tagalog is, however, understood by a big majority of the population as well as the English language. The big influencing factors include the movies, radios, television and publications. English remains the medium of instruction in schools, colleges, and other higher learning institutions.
Generally, the Roman Catholic religion still claims the biggest number of followers, consisting of 893,726, representing 79.160% of the total population. A summary presentation of household population by religious affiliation by city/municipality in the year 2000.
Of the five cities, Tanjay has the highest percentage of Roman Catholic believers with 96.698 per cent, followed by Dumaguete City with 89.230 percent. Bais City has the least Roman Catholic believers with only 49,847 or 73.252 per cent of the total number of Roman Catholics in the province.
Of the 20 municipalities, Dauin had the highest percentage of Roman Catholic believers with 97.090 per cent. Vallehermoso followed with 96.387 per cent. Tayasan got the lowest Catholic believers with 39.832 per cent. The Philippine Independent Church or Aglipayan has more followers than the United Church of Christ in the Philippines.
As of 2000, Dumaguete had the most number of ethnics numbering 101,620. Bisaya got the highest number with 78,258, followed by Cebuano with 20,459. Aburlin, Badjao, Sama Dilaut, Bantoanon, Davao-Chavacano, Gubatnon, Ibaloi/ Inibaloi, Ibontoc, Isamal Kanlaw, Iyapplai, Iyiwaks, Kalinga and Yakan were among those with the least number of ethnics. Minority groups are Batak/Binatak, Dibabawon, Hanunuo, Iraya, Isarog, Isnag, Itawis, Jawa Mapun, Kabihug, Kagayanen, Kamayo, Kapul, Mananwa, Mandaya, Mangyan, Nilulubo, Paranan and Subanen. Canlaon has the least number of ethnics with 46,537. Of the 20 municipalities, Guihulngan had the most number of ethnics with 84,573 individuals while San Jose got the least with 15,658 inhabitants/individuals.