According to the United States Census Bureau, the city has a total area of 6.7 square miles (17 km2).

Laguna Hills is built on one of the major land grants developed during the rancho era.

Following Mexico's independence from Spain in 1821, those who had served in the government or who had friends in authority, were given vast lands for cattle grazing.

Don Juan Avila was granted the 13,000-acre Rancho Niguel on which Laguna Hills is located.

In 1894, Lewis Moulton purchased Rancho Niguel from Don Juan Avila and increased the original grant to 22,000 acres (89 km2).

Moulton and his partner, Jean Piedra Daguerre, used the ranch to raise sheep and cattle.

The Moulton Ranch was eventually subdivided in the early 1960s, and part of the division became today's Laguna Hills.

Incorporation efforts began in 1987 and on March 5, 1991, 86% of the residents voted in favor of forming the City of Laguna Hills.

There were 11,046 housing units at an average density of 1,649.9 per square mile (637.0/km2), of which 7,820 (74.7%) were owner-occupied, and 2,649 (25.3%) were occupied by renters.

In 2020, however, Joe Biden became the first Democratic presidential nominee to win the city since its incorporation.

According to the California Secretary of State, as of February 10, 2019, Laguna Hills has 18,217 registered voters.

[7] Laguna Hills is home to one of the California DMV field offices, where driving tests and other services are administered.

The office serves much of south Orange County as the only other location in the region is in San Clemente.

There is also the MemorialCare Saddleback Medical Center, a hospital equipped with a full emergency room.

Centers of economic activity include: Laguna Hills is served by the Saddleback Valley Unified School District.