Dhaka city is experiencing rapid urbanization with high economic growth and industrial development. Instead of taking a variety of poverty mitigation and social safety programs, the overall number of people living in the informal urban settlements is increasing at a faster rate than the urban population due to the growing figure of internally displaced people by environmental and socio-economic impacts. This study explores the spatiotemporal growth of city’s irregular and informal settlements occupied by rural–urban migrants, utilizing geographical information systems (GIS) and remote sensing and looks into its impact on the changing land use and land cover pattern and urban built environment. Informal settlements had mapped through the visual interpretation of Google high-resolution image focusing temporal patterns of 2006, 2010 and 2016. The land use analysis shows that cultivated land and water bodies all decreased in the area while built-up areas, bare soil, and informal settlements increased over the same period with the encroachment of low-lying lands for settlements.