Background: Temporal change detection of informal settlement was conducted using geographic information system and remote sensing in order to evaluate the land use land cover change (LULCC) in Jimma city, southwestern Ethiopia. We analyzed the LULCC since 1997 using Landsat imagery of 1997, and aerial photography of 2007 and 2017. Qualitative and quantitative data was also collected from city residents by using structured questionnaires focusing on peoples' perceptions to understand the pattern of informal settlements in the study area. Maximum likelihood supervised classification methods was employed to create the signature class of the five land cover classes: built up, vegetation, barren land, open land and agricultural land. Results:The results indicated that the informal settlement has been increased in the peripheries from 29% in 1997, 37% in 2007 and 41% in 2017. This study focuses on the continued transformation of various land uses into informal settlements, causing encroachment on agricultural and open land particularly in the city periphery. The unprecedented population growth and unplanned development activities in urban areas results in urban agglomeration, which increase the price of land market for construction. This implies that rapid population growth, shortage of formal housing and unaffordable cost of formal housing for urban dwellers contributed to informal settlements. Conclusions:Increasing urbanization and rapid population growth are often associated with the development of urban informal settlements. Informal settlements and urban informality are the common problems particularly in the periphery of Jimma city. These results can be used as a basis for informal settlement assessment in other cities in the country and beyond. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.