Urbanization has been defined as an inter-sectoral trend that directly encompass all aspects of human civilization and the economy. The major driver of rapid urbanization in Kenya is demographic dynamics. Urban population in Kenya has been on the rise since the inception of census activities in Kenya in 1897. Based on KNBS findings, it is projected that by 2050, 55% of the entire country’s population will be living in urban areas. This trend has had major influence so far on the nature of our landscape with most arable lands, protected areas, riparian reserves and wetlands in Nairobi City County paving way for urban developments. This project employed the use of Remote Sensing Technologies, GIS Technologies and AHP Multi-Criteria decision-making tool to map urbanization and analyze its effect on quantity of arable land in Nairobi City County. The study was in a position to map and categorize arable lands in the county based on their level of suitability for crop farming as Very Highly Suitable, Highly Suitable, Suitable and Low Suitability areas. Nairobi City County has undergone rapid urbanization in the past two decades with the annual rate of urbanization standing at 5.02% as per the findings of this project. From the findings of this project, approximately 4,514 Hectares of land considered suitable for crop farming were lost to Built-Up Areas as from the year 2000 to 2018. This clearly highlights the impact magnitude that development of urban areas has had on the quantity of arable land.