State Route 387, also known as SR 387, is a state highway in south-central Arizona, United States traveling from State Route 87 west of Coolidge west to Interstate 10, then south to its junction with State Route 84 and State Route 287 in Casa Grande.

SR 387 is a 15.71-mile (25.28 km) highway that connects Casa Grande with I-10 and SR 87. The southern terminus of the highway is located at an intersection with SR 84 and SR 287 in Casa Grande. It heads north through the city from this intersection to the Gila River Indian Reservation before reaching I-10. After the interchange with I-10, the highway intersects SR 187, with SR 387 turning towards the east at the intersection. The highway continues to the east-northeast until it reaches its northern terminus at SR 87.

The route was established between 1946 and 1951, from SR 187 to SR 87 just south of Sun Lakes. Between 1958 and 1961, it was cancelled, and became part of SR 93, a proposed extension of US 93. In 1967, SR 387 was designated from SR 93 to SR 87. It extended south over part of SR 93 on December 17, 1984.

The entire route is in Pinal County.

Location	mi	km	Destinations	Notes
Casa Grande	0.00	0.00	SR 84 (Gila Bend Highway / 2nd Street) / SR 287 to I-8 east (Florence Boulevard) / I-10 – Gila Bend, San Diego, Coolidge, Tucson	Southern terminus of SR 387, western terminus of SR 287
Gila River Indian Community	8.56	13.78	I-10 – Tucson, Phoenix	Exit 185 on I-10
	8.79	14.15	SR 187 north – Sacaton	Southern terminus of SR 187
	15.71	25.28	SR 87 – Chandler, Coolidge, Florence	Northern terminus
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

• SR 387 at Arizona Roads