Casas Adobes (Spanish: "Adobe Houses") is an unincorporated community and census-designated place (CDP) located in the northern metropolitan area of Tucson, Arizona (in Pima County). The population was 66,795 at the 2010 census. Casas Adobes is situated south and southwest of the town of Oro Valley, and west of the community of Catalina Foothills.

The attempted assassination of Representative Gabby Giffords, and the murders of chief judge for the U.S. District Court for Arizona, John Roll, and five other people on January 8, 2011, took place at a Safeway supermarket in Casas Adobes.

Though Casas Adobes is an unincorporated community, it is older than both the towns of Oro Valley and Marana.

The area bordering the Cañada del Oro in the north, and the Rillito River in the south was primarily inhabited and utilized by cattle ranchers. Cattle ranches dominated the Casas Adobes area until the 1920s, when Tucson had grown far enough north and the advent of the automobile made the area more easily accessible.

One of the first individuals to build a home in the area was Maurice L. Reid, who came to Tucson in 1923 seeking a "walking cure" for tuberculosis. In the late 1920s Reid bought a 1,500 acres (6.1 km2) former ranch, bounded by North Oracle Road to the east, Orange Grove Road to the south, Ina Road to the north, and North La Cholla Boulevard to the west. Reid planted more than 200 acres (0.81 km2) of citrus trees and date palms, that would become the heart of Tucson's citrus industry. Over the years, Reid sold parcels of land for home sites, and in 1950 he sold the last of his land. Some larger residential estates continue to maintain the remaining citrus groves and orchards nearly a century later.

Leonie Boutall, who relocated to Arizona from Tennessee, decided to build a guest ranch in the early 1930s. The dry climate, her doctor told her, would relieve her bronchial troubles. Boutall bought 100 acres (0.40 km2) of former ranch land just west of North Oracle Road, and south of a narrow dirt track now called Orange Grove Road. She built Rancho Nezhone, a luxury guest ranch that drew the rich and famous to the sparsely settled area far north of Tucson. Kate Smith, Liberace, Gen. John Pershing and William "Hopalong Cassidy" Boyd were guests of the desert retreat which featured lush vegetation with monkeys and parrots. Boutall sold out of the property in 1948. Today the site is home to Mission Palms Apartments, where much of the original flora and several features remain, including a 300-stone wall in front of the property.

Sam Nanini and Giaconda, his wife, moved to Tucson in 1948 seeking to cure Giaconda Nanini's bronchial asthma. Beginning in the mid-1950s, the Italian born, transplanted Chicagoan developed three residential subdivisions on about 300 acres (1.2 km2) that became the heart of the Casas Adobes community, giving the community its name. The subdivisions, along with Sam Nanini's landmark Casas Adobes Plaza, were considered by many to be Tucson's first suburb. Most of the homes in the subdivision are large ranch-style homes built with adobe bricks. Sam Nanini and his son William also later built the world-class Tucson National Resort, and the million-dollar residential subdivision, the Tucson National Estates.

In 1997, the Arizona legislature passed a law that suspended the ability of incorporated cities and towns in Pima County to prevent the incorporation of other cities within six miles of their borders for a period of approximately two years. That same year, the residents of Casas Adobes voted to incorporate as their own city. However, a series of appeals overturned the new law on constitutional grounds, and the Superior Court annulled the incorporation. A second vote for incorporation in 2001 failed 56 to 44 percent.

Casas Adobes community has grown to encompass a 23-square-mile (60 km2) area inhabited by nearly 60,000 residents. While Casas Adobes' neighboring municipalities of Oro Valley, Marana and Tucson continue to build new homes and shopping centers, Casas Adobes is mostly built out. With the failure of incorporation attempts, it is likely that one or all three of the neighboring entities will annex portions of Casas Adobes in the future.

On January 8, 2011, 19 people were shot during a Congresswoman's meeting in a Safeway grocery store parking lot. Six people were killed, including a federal judge, John Roll, and a congressional aide. U.S. Representative for Arizona's 8th congressional district, Gabby Giffords, was shot in the head at close range. A 22-year-old local man named as Jared Lee Loughner was arrested in connection with the incident.

Casas Adobes is located at 32°20′47″N 111°0′35″W / 32.34639°N 111.00972°W / 32.34639; -111.00972 (32.346368, −111.009844).

According to the United States Census Bureau, the CDP has a total area of 22.6 square miles (58.6 km2), of which 22.6 square miles (58.6 km2) is land and 0.04% is water.

As of the census of 2000, there were 54,011 people, 22,066 households, and 14,718 families residing in the CDP. The population density was 2,386.7 inhabitants per square mile (921.5/km2). There were 23,655 housing units at an average density of 1,045.3 per square mile (403.6/km2). The racial makeup of the CDP was 88.7% White, 1.7% Black or African American, 0.7% Native American, 2.2% Asian, 0.1% Pacific Islander, 4.5% from other races, and 2.3% from two or more races. 13.8% of the population were Hispanic or Latino of any race.

There were 22,066 households, out of which 29.8% had children under the age of 18 living with them, 54.3% were married couples living together, 9.2% had a female householder with no husband present, and 33.3% were non-families. 26.9% of all households were made up of individuals, and 10.2% had someone living alone who was 65 years of age or older. The average household size was 2.40 and the average family size was 2.93.

In the CDP, the population was spread out, with 23.0% under the age of 18, 8.0% from 18 to 24, 28.2% from 25 to 44, 24.6% from 45 to 64, and 16.1% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 90.2 males. For every 100 females age 18 and over, there were 86.7 males.

The median income for a household in the CDP was $49,736, and the median income for a family was $57,926. Males had a median income of $40,323 versus $29,892 for females. The per capita income for the CDP was $24,230. About 3.9% of families and 5.3% of the population were below the poverty line, including 5.2% of those under age 18 and 5.0% of those age 65 or over.

Casas Adobes is served by three public school districts:

Pima County Public Library operates the Nanini Branch Library in Casas Adobes.

Casas Adobes is the location of one of southern Arizona's largest and most biologically diverse nature preserves. Tohono Chul Park is a private nature park located northwest of North Oracle and West Ina roads on North Paseo del Norte. Tohono Chul, Tohono O'odham for "desert corner," was created in 1985 after Richard and Jane Wilson dedicated their historic home and property to the preservation of the desert and the education of visitors on the splendor of the native plants and wildlife.

Casas Adobes features one of the highest concentrations of Mid-century modern architecture in the Tucson area with many prominent architects including Friedman and Jobusch, Nicholas Sakellar, Tom Gist, and Edward Nelson designing properties in the region. Notable examples include Saint Odilia Catholic Church, St Andrew's Presbyterian Church, Dove of Peace Lutheran Church, Arizona Bank (now Bank of America) as well as numerous residences in Catalina Village, Westward Look Estates, Casas Adobes Estates and Samalayuca Estates among other neighborhoods.

The Casas Adobes Plaza is a retail destination, dating back to 1948. The Plaza is situated on the southwest corner of North Oracle and West Ina roads, and features some of the most authentic Mediterranean architecture in the area. Original Italian vignettes, statues, and fountains are incorporated into the plaza. Casas Adobes Plaza has a historic Mediterranean observation tower.

Westward Look Resort is located in Casas Adobes, beginning in the early 20th century as a dude ranch in the foothills of the Santa Catalina Mountains north of Tucson. The property was significantly expanded in the late 1960s by modernist architect Edward Nelson and became the Tucson area's first resort. The original adobe home commissioned by ranch founders William and Maria Watson in the 1910s by Tucson architect Merritt Starkweather remains the heart of Westward Look Resort and is named the "Vigas Room."

Casas Adobes has a nationally prominent golf resort built in the 1960s by Sam Nanini, the Omni Tucson National Resort. Hosting the PGA Tour Tucson Open for more than forty years, golfers Jack Nicklaus (who was discovered and promoted by Nanini), Arnold Palmer, Lee Trevino, Tom Watson, Tom Kite and Johnny Miller have played at Tucson National. Early tournaments were celebrity-hosted by Dean Martin and others.

While Casas Adobes remains unincorporated, the community has distinguished itself from the other suburbs to the north and northwest of Tucson as the oldest community.