Toponyms, along with other urban symbols, were used as a tool of control over space in many African countries during the colonial period. This strategy was epitomized by the British, who applied it in Nairobi and other parts of Kenya from the late 1800s. This paper shows that toponymy in colonial Nairobi was an imposition of British political references, urban nomenclature, as well as the replication of a British spatial idyll on the urban landscape of Nairobi. In early colonial Nairobi, the population was mainly composed of three main groups: British, Asians, and Africans. Although the Africans formed the bulk of the population, they were the least represented, socially, economically and politically. Ironically, he British, who were the least in population held the political and economic power, and they applied it vigorously in shaping the identity of the city. The Asians were neither as powerful as the British, nor were they considered to be at the low level of the native Africans. This was the deliberate hierarchical structure that was instituted by the colonial government, where the level of urban citizenship depended on ethnic affiliation. Consequently, this structure was reflected in the toponymy and spatial organization of the newly founded city with little consideration to its pre-colonial status. Streets, buildings and other spaces such as parks were predominantly named after the British monarchy, colonial administrators, settler farmers, and businessmen, as well as prominent Asian personalities. In this paper, historical references such as maps, letter correspondences, monographs, and newspaper archives have been used as evidence to prove that toponyms in colonial Nairobi were the spatial signifiers that reflected the political, ideological and ethnic hierarchies and inequalities of the time.