The topography of Lanham is generally flat to gently rolling, characteristic of the inner Coastal Plain of Maryland just east of the Atlantic Seaboard fall line. The elevation averages around 150 to 160 feet above sea level, with very few steep gradients.
There are no major mountains or deep valleys within the community limits. The terrain gently slopes toward local creek beds, such as Folly Branch and the upper tributaries of the Northeast Branch of the Anacostia River. These slight depressions serve as natural drainage basins and have been heavily integrated into the community's stormwater management and local park infrastructure.