State Route 243 (SR 243), or the Banning-Idyllwild Panoramic Highway, is a 30-mile (50 kilometer) two-lane highway that runs from Banning, California (in the north) to Idyllwild, California (in the south) in Riverside County, California, USA. In 2007, it was named the Esperanza Firefighters Memorial Highway in honor of five firefighters who died while fighting the Esperanza Fire on 26 October 2006.

State Route 243 is mainly a connector between Interstate 10 and State Route 74. However, along its route it provides access for many truck trails that run through San Bernardino National Forest. These truck trails provide access to smaller towns such as Pine Cove.

The route is generally considered to be a minor artery, with the heaviest traffic near the Idyllwild segment of the highway. The rest of the highway is mostly a rural two-lane segment until Banning and the terminus at Interstate 10. This route is eligible for the State Scenic Highway System and is classified as a Scenic Highway in California.

SR 243 begins at SR 74 in the San Bernardino National Forest as Idyllwild Road and traverses north along a winding road through the community of Idyllwild. The road makes a left turn at the intersection with Circle Drive and continues as Idyllwild Road through Pine Cove. SR 243 continues through the forest through Twin Pines and the Morongo Indian Reservation before making a few switchbacks en route to the city of Banning. The highway continues as San Gorgonio Avenue before making a left onto Lincoln Street and a right onto 8th Street before terminating at I-10.

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, and do not necessarily reflect current mileage. The entire route is in Riverside County.