Marsabit County had a population of 459,785 persons, comprising 243,548 males (52.9%), 216,219 females (47.1%), and 18 intersex individuals as of 2019 (KNBS, 2019). The population has been growing at an annual rate of 3.4%, and as of the 2023–2024 Kenya Housing and Survey Report (KNBS, 2024), it is estimated to have risen to 515,292. The gender distribution is almost balanced, with 49.7% male and 50.3% female.

Marsabit County’s population is youthful, with approximately 58% of residents aged below 19 years, signaling a high future energy demand for households, education, and productive services. The county has a low average population density of 6 persons/km², though this varies significantly by sub-county – posing a significant bottle neck to infrastructure development.

Saku Sub-County, home to the county headquarters, is the most densely populated at 37 persons/km², while North Horr is the most sparsely populated, with just 3 persons/km² (KNBS, 2024).

The average household size is 5.8 persons per household, which has implications for residential energy consumption patterns, particularly in cooking and lighting. Marsabit County’s population is mainly composed of pastoralist communities, with the Gabbra, Rendille, and Borana being the most prominent ethnic groups.