The Jeffrey Open Space Trail is a public park in Irvine, California, planned to stretch for 5 miles (8.0 km) along a corridor on the east side of Jeffrey Road, from Quail Hill in the San Joaquin Hills inland to Portola Parkway in the Santa Ana Mountains. Bridges and underpasses allow pedestrians and bicyclists to use the trail without having to interact with the streets and freeways that it crosses.
The space along the east side of Jeffrey Road had originally been set aside for a future monorail system and was therefore left open and unbuilt, with the sections bordering Irvine Valley College and Oak Creek Golf Club being used as strawberry fields. The first segment of the trail, between Trabuco Road and Irvine Boulevard in north Irvine, was completed in 2006. In 2007, the design for the park won an Honor Award at the Design Awards of the Southern California Chapter of the American Society of Landscape Architects. As of 2015, 76 acres (31 ha) of parkland extending 3.5 miles (5.6 km) between Portola Parkway and Interstate 5 has been completed; another segment east of Portola Parkway is projected to open by 2020.