State Route 73 (SR 73) is a state highway in the U.S. state of California, running from the junction with Interstate 405 in Irvine through the San Joaquin Hills to its junction with Interstate 5 in San Juan Capistrano, its northern and southern terminii, respectively. The entirety of the route is located in Orange County. From its northern terminus, the first three miles (5 km) of the highway are called the Corona del Mar Freeway; this section of highway opened in 1978. The next 12 miles (19 km) of the 15-mile (24 km) highway, completed in November 1996, are a toll road operated by the San Joaquin Hills Transportation Corridor Agency named the San Joaquin Hills Transportation Corridor. Its alignment follows an approximately parallel path between the Pacific Coast and the San Diego freeways. There are no HOV lanes currently, but the medians have been designed with sufficient clearance for their construction should the need arise in the future.

State Route 73 is part of the California Freeway and Expressway System. SR 73 begins in San Juan Capistrano at an interchange with I-5. The freeway heads northwest into the city of Laguna Niguel before the tolled portion begins at the Greenfield Drive exit. SR 73 continues into the city of Aliso Viejo before entering Laguna Beach, where SR 73 intersects SR 133 with a separated-grade exit. Following this, the road passes through Crystal Cove State Park, where the main toll plazas are located. After leaving the state park, SR 73 straddles the border between Irvine and Newport Beach and provides easy access to University of California, Irvine through the Bison Avenue exit. Following the MacArthur Boulevard exit, the tolled part of the road ends. SR 73 continues into Newport Beach, running along the southern boundary of Orange County John Wayne Airport (IATA Airport Code SNA). Entering Costa Mesa, SR 73 interchanges with SR 55 before merging with I-405 and terminating the route.

Most of State Route 73 is a limited-access toll highway designed to reduce congestion within Orange County on the Pacific Coast Highway (State Route 1) and the San Diego Freeway (Interstates 5, and 405) by providing a direct route through the San Joaquin Hills.

State Route 73 is not a toll road over its entire length. From its northbound terminus heading southbound, the first three miles (5 km) of State Route 73 have no tolls and make up the entire Corona Del Mar Freeway. State Route 73's previous alignment had the freeway portion end at MacArthur Boulevard, and the SR 73 designation ran along MacArthur south to meet Route 1 in Corona del Mar. Under the current alignment, heading southbound, State Route 73 becomes a designated toll road immediately after the Jamboree/MacArthur ramp and remains so until its southern terminus at I-5. Though the next ramp heading southbound (Bison Avenue) is part of the toll road, it is toll-free, as is the first ramp heading northbound from the southern terminus (Greenfield Drive).

Design and construction of the highway cost a total of $800 million. The design and construction was overseen by the San Joaquin Hills Transportation Corridor Agencies, or SJHTCA, an agency formed in 1986 for the express purpose of designing the tollway. In the end, State Route 73 included 10 interchanges, 68 bridges, 725 000 square feet (67,000 m²) of retaining walls, and 32 million cubic yards (24,000,000 m³) of excavation at completion. Construction was divided into four different sections, each with its own management system and quality control. A joint venture led by Kiewit Pacific Co., a subsidiary of Kiewit Corporation, completed this project.

State Route 73's toll road was the first to be financed with tax-exempt bonds on a stand-alone basis including construction and environmental risk.

The tolls on SR 73 begin only after the Bison Ave. exit in the southbound direction. In the northbound direction, there is a toll in effect after Greenfield Drive, the first ramp north of the highway's terminus. Travelers who drive the entire length of the 73 will only encounter one toll booth, the Catalina View Toll Plaza. Patrons who use an exit along the toll road are charged a prorated toll.

Since its inception, the San Joaquin Hills toll road has used the FasTrak electronic toll collection system, allowing drivers to travel the entire distance without stopping or even slowing down as their tolls are collected electronically by overhead radios reading the transponder mounted on the vehicle. Travelers using FasTrak pay a discounted toll. FasTrak patrons may also drive through cash-designated lanes at any toll plaza without stopping. The radio receivers overhead detect the vehicle before it even approaches the cash deposit area and automatically turns the traffic light green.

The following table lists the tolls at each of the tolled exits, both with and without FasTrak:

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 Orange County.