According to the United States Census Bureau, the city has a total area of 14.9 square miles. 14.8 square miles of it is land and 0.05 square miles of it (0.35%) is water.

Laguna Niguel occupies a hilly basin near the southern end of the San Joaquin Hills, a small coastal mountain range in southern Orange County. On the west is 650-foot Niguel Hill, which separates the city from Aliso Canyon, an immense gorge cut by Aliso Creek, one of the county's primary watercourses. The Aliso Canyon area is home to Aliso and Wood Canyons Regional Park, a large wilderness area in the southern county.

Although the creek itself only brushes the northwestern border of the city, a major tributary, Sulphur Creek, drains most of northern Laguna Niguel. Sulphur Creek runs through Crown Valley in eastern Laguna Niguel, Crown Valley Park, Laguna Niguel Regional Park and Sulphur Creek Reservoir (Laguna Niguel Lake). The two parks and the lake lie just north of the geographic center of the city.

Low ridges dissect much of the Laguna Niguel area. Most of these mountain ridges, some of them attaining heights of one or two hundred feet, run northeast to southwest, delineating the hydrography of the area. Laguna Niguel's other primary drainage, Salt Creek, has two forks in the southern half of the city, flowing southwards to the Pacific Ocean.

Laguna Niguel itself has no border on the ocean. The city of Dana Point to the south separates Laguna Niguel and the Pacific. On the east side, Laguna Niguel is separated from San Juan Capistrano by a significant ridge running along Trabuco Creek. To the north lie Aliso Viejo and Laguna Hills.

Crown Valley and Alicia Parkways are the primary thoroughfares in the city. Crown Valley Parkway runs along Sulphur Creek and the northern fork of Salt Creek, bisecting the city northeast to southwest. Alicia Parkway, mostly a north-south road, follows Aliso Creek to where it joins Crown Valley Parkway in close proximity to Crown Valley Park and the city center.

California State Route 73 runs north of the city, diverging from Interstate 5 just northeast of Laguna Niguel. Moulton Parkway/Street of the Golden Lantern runs along the eastern boundary of Laguna Niguel. Pacific Island Drive/Camino del Avión follow parts of the west and south boundaries, respectively. Another major road, Niguel Road, runs roughly parallel and east of Crown Valley Parkway along the Salt Creek canyon. Marina Hills Drive is the largest crossing between Niguel Road and Golden Lantern, and Aliso Creek Road runs east-west through northern Laguna Niguel.

The 2010 United States Census reported that Laguna Niguel had a population of 62,979. The racial makeup of Laguna Niguel was 50,625 White, 777 African American, 219 Native American, 5,459 Asian, 87 Pacific Islander, 3,019 from other races, and 2,793 from two or more races. Hispanic or Latino of any race were 8,761 persons.

As of the census of 2000, there were 61,891 people, 23,217 households, and 16,785 families residing in the city. The population density was 4,221.0 inhabitants per square mile. There were 23,885 housing units at an average density of 1,629.0 per square mile. The racial makeup of the city was 83.50% White, 1.25% African American, 0.29% Native American, 7.73% Asian, 0.12% Pacific Islander, 3.48% from other races, and 3.62% from two or more races. Hispanic or Latino of any race were 10.38% of the population.

There were 23,217 households out of which 38.1% had children under the age of 18 living with them, 60.2% were married couples living together, 8.8% had a female householder with no husband present, and 27.7% were non-families. 20.6% of all households were made up of individuals and 4.7% had someone living alone who was 65 years of age or older. The average household size was 2.65 and the average family size was 3.10.

In the city the population was spread out with 26.6% under the age of 18, 6.0% from 18 to 24, 32.9% from 25 to 44, 25.7% from 45 to 64, and 8.9% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 94.9 males. For every 100 females age 18 and over, there were 91.2 males.

According to the Census Bureau's 2008 estimate, the median income for a household in the city was $98,072, and the median income for a family was $120,963. Males had a median income of $68,640 versus $40,487 for females. The per capita income for the city was $50,980. About 2.8% of families and 4.1% of the population were below the poverty line, including 3.6% of those under age 18 and 4.1% of those age 65 or over.

The City Council consists of five members, elected from the City at-large, who serve four year staggered terms. Annually, the City Council appoints a Mayor and a Mayor Pro Tem from its own membership to serve a one-year term. Current incumbents are:

The city has recently completed a permanent City Hall complex at the corner of Alicia Parkway and Crown Valley Parkway.

In The Orange County Board of Supervisors Laguna Niguel is part of the 5th District. In the state legislature Laguna Niguel is located in the 33rdSenate District and in the 73rd Assembly District. Federally, Laguna Niguel is located in California's 48th congressional district.

Like much of Southern California, Laguna Niguel has pleasant weather year-round. On average, August is the hottest month and December the coolest. The highest recorded temperature is 108°F, which occurred in 1963, and the lowest such temperature is 21°F, which was recorded in 1949. Precipitation is sparse in Laguna Niguel, as only five months out of the year receive rainfall greater than one inch. The highest monthly rainfall on average occurs in February and is 2.96 inches.

In 1971, a one-million square-foot Ziggurat building (Ziggurats are, architecturally, the Mesopotamian equivalent of the Egyptian pyramids; large artificial square mountains of stone), originally built for Rockwell International and presently owned by the United States government, was designed by Los Angeles-based architect William Pereira.

The Chet Holifield Federal Building, as it is now known, is home to millions of microfilms as documents of land agreements between the American government and the original Indian Tribes of the southwest United States. It is also home to the Western Regional Department of Homeland Security and the California Service Center of the United States Citizenship and Immigration Services.

The Chet Holifield Federal Building was used for the 1995 movie Outbreak, where it served as the exterior for the Center for Disease Control headquarters. Earlier, the building was featured in an ending scene for the 1975 sci-fi movie Death Race 2000.

The city is served by the Capistrano Unified School District.

It is served by:

Elementary schools

• Moulton Elementary School
• Marian Bergeson Elementary
• Crown Valley Elementary School
• Hidden Hills Elementary School
• Laguna Niguel Elementary School
• Malcolm Elementary School
• George White Elementary School

Middle schools

• Niguel Hills Middle School
• Aliso Viejo Middle School (in Aliso Viejo)

High schools

• Aliso Niguel High School (in Aliso Viejo)
• Dana Hills High School (in Dana Point)

Colleges

• Saddleback College (in Mission Viejo - Served by the South Orange County Community College District)
• Chapman University (in Orange)
• Soka University of America (in Aliso Viejo)
• University of California, Irvine (in Irvine)
• California State University, Fullerton (in Irvine)
• California State University, Fullerton (in Fullerton)

Private schools

• St. Anne School

Over one-third of Laguna Niguel is designated as open space. Major parks in the city include:

• Aliso/Wood Canyons Regional Park
• Badlands Park
• Laguna Niguel Regional Park

Laguna Niguel is home to many upscale neighborhoods including Bear Brand Ranch, Ocean Ranch, Coronado Pointe, South Peak, Crest de Ville, Niguel Coast, Palmilla, and Monarch Point, which offer city, canyon, and ocean views. Other major neighborhoods include Rancho Niguel, Marina Hills, Niguel West, Niguel Summit, Beacon Hill, El Niguel Heights, Kite Hill, and San Joaquin Hills.