Previous studies on urban land use/cover change emphasised the role of economic forces in producing population growth and its attendant land use/cover changes, almost to the exclusion of other important factors. In spite of a swelling literature on land use/land cover changes, studies comparing these changes before and after changes in the administrative status of cities are rare. This study therefore investigates the effect of change in the administrative status of a medium-size city on the urban expansion and land use/cover change with specific interest in assessing the trends and spatial patterns of land use/cover changes in pre-capital city period (1972-1991) and post-capital city period (1996-2016) of Osogbo, Nigeria. Landsat MSS, TM and ETM+ imageries (1972, 1986, 1991, 1996, 2006, and 2016) and population data were used in this study. Maximum Likelihood Classification was employed to categorise the images into built-up areas, vegetation cover, and water bodies. The study revealed that the city expanded axially along major lines of communication in the pre-capital years while some were filling up and intensification of urban land use was noticed in the post-capital years. While the built-up area grew at an annual rate of 2.8% in pre-capital status years (1972 to 1991), the growth accelerated in post-capital status periods (1996 to 2016) 4.7% annually. This study has shown that change in the administrative status of the city contributes to the city’s land use/cover changes through accelerated expansion in areal coverage and densification of the urban land use with attendant loss of vegetation and water bodies. City managers, therefore, should consider future changes in cities’ administrative role in their urban land use planning.