State Route 188 or SR-188 is a 19.686-mile (31.682 km) state highway that serves as an east-west connection through southern Mobile County. SR-188 intersects Interstate 10 at its western terminus and SR-193 at its eastern terminus.

State Route 188 begins just north of its intersection with I-10 north of Grand Bay. From this point, the route travels in a southerly direction through a brief concurrency with US-90 before taking a southeasterly course upon leaving Grand Bay. SR-188 continues its southeasterly course just prior to reaching Bayou La Batre where it turns to the south and remains in a north-south orientation. Upon its exit from Bayou La Batre, SR-188 returns to its easterly course through its eastern terminus at SR-193.

The entire route is in Mobile County.