The Orange Redevelopment Agency was established by the City Council on August 11, 1983, with the adoption of Ordinance No. 21-83. The City Council serves as the governing Board of Directors of the Agency. Pursuant to California Redevelopment Law, the Agency is a separate public body and may exercise its own governmental functions in planning and implementing redevelopment projects.

The Tustin Street Project Area, adopted in December 1983 and amended in 1988, totals over 1,000 acres and encompasses all frontal commercial properties along Tustin Street from the southerly City limits, extending beyond Lincoln Avenue to the north; east on Chapman to Yorba Street; and on Katella Avenue west to California Street and east to the Costa Mesa Freeway (Route 55).

The Southwest Project Area, adopted in 1984 and amended in 1986, 1988 and 1996, encompasses nearly 900 acres that include the City's southwest quadrant and the Old Towne Historic District. This Southwest Project Area is comprised of most commercial properties in that sector of the City.

Adopted in 1988, the Northwest Project Area, as its name implies, is comprised of approximately 1,680 acres in the City's northwest sector, much of which has been commonly identified as the industrial area of the City.

Activities in the City's three project areas all relate to the three-fold mission of the Agency: to enhance the commercial and industrial areas of the City; to revitalize those areas; and to increase, improve and preserve the community's supply of Low and Moderate Income housing available at affordable housing cost. Housing activities funded by the State-mandated twenty percent set-aside of tax increment received by the agency must be used to increase, improve and preserve the City's supply of affordable housing. Housing funds can, upon making a finding of benefit to the project, address housing needs in all neighborhoods within the city limits.

In 2001, the three redevelopment project areas were merged into one, which is known as the Orange Merged and Amended Redevelopment Project Area.