In the 2020 census, the population of Kidapawan was 160,791 people,^[4] with a density of 450 inhabitants per square kilometre or 1,200 inhabitants per square mile.

In the 2015 census, the city had a total population of 140,195 people, ^[15] up from 125,447 people in 2010 ^[16] and 117,610 from in 2007. The religion is predominantly Christian, although there are many Muslims residing in the city as well. The main languages are Cebuano and Hiligaynon, while English functions as a secondary language. Other languages spoken include Obo Monuvu (the city's indigenous language) Maguindanaon, Meranaw, Ilianen, and Tagabawa.

Obo Monuvu, Cebuanos and Hiligaynons are the major ethnic groups in the city. Other ethnic groups residing in the area are the Ilocanos, Maguindanaons and Manobo groups of Obo, Ilianen, and Tagabawa. Cebuano is the most widely spoken language, especially in the city proper. English is used as the medium of instruction in schools and other learning institutions; it is also predominantly used in major government agencies in their transactions and reports. Laws and ordinances in the city are all written in English.