Located in Gary's southwest corner, Black Oak adjoins the City of Hammond to the west, and the Town of Griffith and unincorporated Calumet Township to the south.

Black Oak is the only neighborhood in Gary where mobile homes make up a significant fraction of total housing.

[5] Commercial development in Black Oak is concentrated at the neighborhood's eastern boundary along the Burr Street and Interstate 80 corridor.

Black Oak has numerous expanses of wetland and undeveloped floodplain land near the Little Calumet River.

[6] The neighborhood includes Lake Sandy Jo, a Superfund site used as a toxic waste dump from 1967 to 1975, when it was closed by court order.