Alsip is a village in Cook County, Illinois, United States. The population was 19,725 at the 2000 census. It is a suburb of Chicago.
Alsip was settled in the 1830s by German and Dutch farmers. The village is named after Frank Alsip, the owner of a brickyard that opened there in 1885. The village began to grow after the Tri-State Tollway was built there in 1959.
According to the United States Census Bureau, the village has a total area of 6.5 square miles (16.9 km²), of which, 6.4 square miles (16.5 km²) of it is land and 0.2 square miles (0.4 km²) of it (2.45%) is water.