State Route 188 is 60.85-mile (97.93 km) state highway located in Gila County in the U.S. state of Arizona.

The route starts at U.S. Route 60 in Claypool, just west of Globe, and runs generally northwest to a junction with State Route 288, then continues alongside Lake Roosevelt. The route junctions with State Route 88, then continues through Tonto Basin and Pumpkin Center. The route originally followed a single-lane road down the canyon wall to the Theodore Roosevelt Dam, then crossed the dam to the other side of the canyon. A two-lane suspension bridge upstream from the dam has now replaced this routing. State Route 188 ends at State Route 87 south of Rye.

Between Claypool and Lake Roosevelt is an old loop road labelled "Old Highway 88"; originally State Route 88 continued down 188 from Lake Roosevelt to US 60 at Claypool. State Route 188 has been widened to a multi-lane highway along part of its length.

The entire route is in Gila County.