For thousands of years before the arrival of European-American settlers, the Atfalati tribe of the Kalapuya lived in the Tualatin Valley near the later site of Hillsboro. The climate, moderated by marine influence from the Pacific Ocean, helped make the region suitable for fishing, hunting, food gathering, and agriculture. Settlers founded a community here in 1842, later named after David Hill, an Oregon politician. Transportation by riverboat on the Tualatin River was part of Hillsboro's settler economy. A railroad reached the area in the early 1870s and an interurban electric railway about four decades later. These railways, as well as highways, aided the slow growth of the city to about 2,000 people by 1910 and about 5,000 by 1950, before the arrival of high-tech companies in the 1980s.
Hillsboro has a council-manager government consisting of a city manager and a city council headed by a mayor. In addition to high-tech industry, sectors important to Hillsboro's economy are health care, retail sales, and agriculture, including grapes and wineries. The city operates more than twenty parks and the mixed-use Hillsboro Stadium, and nine sites in the city are listed on the National Register of Historic Places (NRHP). Modes of transportation include private vehicles, public buses and light rail, and aircraft using the Hillsboro Airport. The city is home to Pacific University's Health Professions Campus. Notable residents include two Oregon governors.
Hillsboro's population grew from 402 in 1880 to 2,016 by 1910, making it the county's most populated city, according to 1910 census data. By 1970, it had increased to more than 15,000, although neighboring Beaverton had overtaken it as the county's most populous city. By 1990 there were more than 37,000 residents, and commuters raised this to 110,000 during daytime. As of 2008, the estimated population was about 89,000, fifth in rank among the state's largest cities behind Portland, Eugene, Salem, and Gresham and slightly ahead of Beaverton, which ranked sixth.
As of the census of 2000, there were 70,187 people, 25,079 households, and 17,078 families residing in the city. The population density was 3,253.8 per square mile (1,256.3/km²). There were 27,211 housing units at an average density of 1,261.5/sq mi (487.1/km²). As of 2007, there were 17,126 houses lived in by their owners, with an average home price in the city of $246,900.
The racial makeup of the city was 77.50% White, 6.53% Asian, 1.22% African American, 0.82% Native American, 0.25% Pacific Islander, 10.38% from other races, and 3.30% from two or more races. Hispanic or Latino of any race were 18.90% of the population. This compares to the state's overall racial makeup of 93.45% White, 2.17% African American, 3.75% Asian, and 7.63% Hispanic.
There were 25,079 households out of which 37.9% had children under the age of 18 living with them, 54.7% were married couples living together, 9.0% had a female householder with no husband present, and 31.9% were non-families. 23.4% of all households were made up of individuals and 5.3% had someone living alone who was 65 years of age or older. The average household size was 2.76 and the average family size was 3.28.
City residents included 28.3% under the age of 18, 11.4% from 18 to 24, 37.0% from 25 to 44, 17.0% from 45 to 64, and 6.3% who were 65 years of age or older. The median age was 30 years. For every 100 females there were 105.6 males. For every 100 females age 18 and over, there were 105.8 males.
The median income for a household in the city was $51,737, and the median income for a family was $57,379. Males had a median income of $41,046 versus $30,172 for females. The per capita income for the city was $21,680. About 6.0% of families and 9.2% of the population were below the poverty line, including 10.9% of those under age 18 and 7.2% of those age 65 or over. As of 2007, 28% of people 25 and older held at least a bachelor’s degree, while an additional 11% held an associate's degree. Those with less than a high school diploma made up 15% of the population, and 22% of residents had more than a high school diploma but less than a college degree.
For the year 2006, the city had 192 violent crimes reported to law enforcement, and 2,752 reports of property crimes. The violent crime rate was 224 per 100,000 people compared to a national average of 474 and 287 for Oregon. Property crime nationally was 3,335 per 100,000 compared to 3,203 in Hillsboro, and 4,402 for the state. Violent offenses include forcible rape, robbery, murder, non-negligent manslaughter, and aggravated assault. Property crimes include arson, motor vehicle theft, larceny, and burglary. Statistics published by the Oregon Criminal Justice Commission showed a slight downward trend in the Washington County crime rate between 1991 and 2005. The rate for index crimes, a group comprising the combined violent offenses and property crimes mentioned above, was 3,930 per 100,000 in 1991 and rose to 4,440 per 100,000 in 1997 before falling to 3,410 per 100,000 in 2005.
Freight rail service from Portland and Western Railroad with interconnections to the BNSF Railway and the Union Pacific Railroad both serve Hillsboro. The city is not served by passenger rail service over heavy rails. Public transportation is available by bus and light rail, managed by regional transit agency TriMet. The first MAX light rail line, now known as the Blue Line, was extended to serve Hillsboro on September 12, 1998. The western terminus is located downtown. The Willow Creek and Hillsboro transit centers (TC) are the main hubs of the public transit system, although seven other MAX stations provide varying degrees of bus interconnection. MAX Stations (west to east) are the Hatfield Government Center, Hillsboro Central TC, Tuality Hospital, Washington Street, Fair Complex / Hillsboro Airport, Hawthorn Farm, Orenco, Quatama, and Willow Creek TC.
Air travel is available at the Hillsboro Airport in the center of the city and at Stark's Twin Oaks Airpark, a general aviation field south of the city. The Hillsboro Airport is a general aviation airport operated by the Port of Portland, and is the second-busiest airport in the state after Portland International Airport. The airport mainly serves private pilots and corporate flights, with no scheduled airline flights from its two runways.
Oregon Route 8, known locally as the Tualatin Valley Highway (TV Highway), is the primary east–west highway. U.S. Route 26, also known as the Sunset Highway, bisects the northeast corner of the city. Other major east–west roads are Cornell Road and Main Street / Baseline Road. Major north–south routes are Oregon Route 219 / 1st Street, 10th Street / Cornell Road, Cornelius Pass Road, and Brookwood. The easternmost north–south route, 185th Avenue, borders Beaverton and runs between the Tanasbourne Town Center and the rest of Hillsboro. TV Highway connects to Cornelius and Forest Grove to the west and Beaverton to the east.
Hospital services in the city are provided by Tuality Community Hospital in downtown. Opened in 1918 as the city's first hospital, the 167-bed facility is operated by Tuality Healthcare. Other significant medical facilities include Kaiser Permanente’s Sunset Medical Office and Providence Health & Services' immediate care center, both in the Tanasbourne neighborhood. Kaiser Permanente received approval in 2007 to build a hospital at the site of its existing medical office in Tanasbourne. Estimated to cost $285 million, the facility will start with 121 beds with a planned capacity of 174 beds when fully built. The Department of Veterans Affairs opened a medical clinic in the Tanasbourne area in 2008.
For more than 150 years, the city has had residents as varied as David Hill, the city's founder, to Tiffeny Milbrett, an Olympic and World Cup champion soccer player. Two governors of Oregon, James Withycombe and Paul L. Patterson, have called the city home. Other politicians included Congressmen Thomas H. Tongue and Samuel Thurston; mayors William N. Barrett, Benjamin P. Cornelius, and William D. Hare, patriarch of the Hare political family. Athletes include Erik Ainge, Scott Brosius, Ad Rutschman, Wes Schulmerich, Wally Backman, and Olympic medalists Josh Inman, Thomas Garrigus, and Jean Saubert. Hillsboro has also been home to Peggy Y. Fowler, the former chief executive officer of Portland General Electric, "Lego Bandit" William Swanberg, producer Bryce Zabel, the "Mother Queen of Oregon" Mary Ramsey Wood, Tommy Overstreet, and professional wrestler Roddy Piper.