Tovaangar (before 1771) Ontario was inhabited by the
Tongva people for over 1,000 years. Their country is now known as
Tovaangar. The Ontario area was connected to the village of
Cucamonga, whose location is not precisely known. The
Spanish Empire's
New Spain Portolá expedition found and named the
Santa Ana River in 1769. They also explored the Cucamonga area.
Spanish Empire (1771–1822) In 1771,
Franciscans from
New Spain settled nearby, and established the
Mission San Gabriel Arcángel, founding what is today
San Gabriel. They enslaved the Tongva people. The area was now part of the New Spain
Province of Las Californias.
Juan Bautista de Anza passed through the area on his 1774 expedition, which created a land route between the province of
Sonora and San Gabriel. An Ontario city park now bear his name. The route became known as the
El Camino Real. In 1804, the northern part of Las Californias became the new province of
Nueva California. In 1810, the San Gabriel Franciscans took over the Tongva village of
Kaawchama (in today's west
Redlands), replacing it with the
Guachama rancheria. This included a chapel devoted to San Bernardino (beginning the association of the saint with the area). The rancheria was destroyed by the
Serrano in 1812, and was rebuilt nearby as the
San Bernardino de Sena estancia in 1819.
Mexico (1822–1847) In 1822, word of the Mexican triumph in the
Mexican War of Independence reached Nueva California, and the lands previously controlled by the Spanish Empire passed to the custody of the
Mexican government. In 1824, the province of Nueva California was renamed
Alta California. In 1826, American explorer
Jedediah Smith passed through what is now
Upland on the first known overland journey from the east coast to the west coast of North America. He used Native American trails that he helped establish as the
California Trail. (This later became the
National Old Trails Road,
Route 66, and today's
Foothill Boulevard.) Use of the San Gabriel mission's
Rancho Cucamonga was in 1839 granted to
Tiburcio Tapia by Alta Californian governor
Juan Bautista Alvarado as part of the
secularization of California land holdings. This emancipated the Tongva enslaved there. The name
Mount San Antonio was probably bestowed by
Antonio Maria Lugo, owner of
Rancho San Antonio near present-day
Compton circa 1840, in honor of his patron saint,
Anthony of Padua. In 1845, Rancho Cucamonga was inherited by Tapia's daughter, Maria Prudhomme, and her husband Leon Prudhomme.
United States (1847 onward) 1800s In January 1847, the
United States took control of the area, after the
conquest of California during the
Mexican-American War, and U.S. control was formalised by the
Treaty of Cahuenga. Under the
Treaty of Guadalupe Hidalgo in 1848, the United States recognised the existing land tenure, and took formal control of the land. It ruled it under a
military administration until a new civilian body was established in December 1849, which became the state of
California in September 1850. In February 1850, the interim California government established
Los Angeles County. (The earlier Los Angeles municipal government did not cover today's Ontario.) The new Californian administration soon began a war of extermination against the Tongva, which came to be known as being part of the
California genocide.
San Bernardino County was founded in 1853, following the establishment of
a new Mormon settlement. A road was built between San Bernardino and Los Angeles that year, passing through Rancho Cucamonga. John Rain's heirs sold Rancho Cucamonga in 1870 to an
Isaias Hellman-led syndicate, the "Cucamonga Company". 20 years after the initial application, the California government formally converted the title of the rancho to freehold in 1872. In 1881, the Chaffey brothers,
George and
William, purchased a parcel of Hellman's Rancho Cucamonga land, and rights to Mount San Antonio water. The brothers established a settlement they named "Ontario" in honor of the
province of
Ontario in
Canada, where they were from. The land was sometimes referred to the "San Antonio lands", as they included half the water rights to
Mount San Antonio (colloquially known as "Mount Baldy"). They engineered a drainage system channelling water from the foothills of the mountain down to the flatter lands below that performed the dual functions of allowing farmers to water their crops and preventing the floods that periodically afflict them. They also created the main thoroughfare of Euclid Avenue (
California Highway 83), with its distinctive wide lanes and grassy median. A mule-drawn passenger tramway was used from 1887 to 1895 on the central reservation the Avenue, operated by the
Ontario and San Antonio Heights Railroad Company. The San Antonio Water Company was incorporated in October 1882. Since then it has served the area that is today Ontario, Upland and, San Antonio Heights, and to a lesser extent Montclair. In 1885, the Chaffey brothers opened a campus of the
University of Southern California. This included a secondary school. Also in 1885, the
Ontario Record newspaper was founded. (It would later be known as
The Daily Report.) The new "Model Colony" (called so because it offered the perfect balance between agriculture and the urban comforts of schools, churches, and commerce) was originally conceived as a
dry town, early deeds containing clauses forbidding the manufacture or sale of alcoholic beverages within the town. Ontario attracted farmers (primarily growing
citrus) and ailing Easterners seeking a drier climate (often to treat
tuberculosis). To impress visitors and potential settlers with the "abundance" of water in Ontario, a fountain was placed at the
Southern Pacific railway station. It was turned on when passenger trains were approaching and frugally turned off again after their departure. The original "Chaffey fountain," a simple spigot surrounded by a ring of white stones, was later replaced by the more ornate "Frankish Fountain", an art nouveau creation now located outside the Ontario Museum of History and Art. Agriculture was vital to the early economy, and many street names recall this legacy. The
Sunkist plant remains as a living vestige of the citrus era. The Chaffey brothers left in 1886 to found the Australian irrigation settlements of
Mildura and
Renmark, selling their Ontario assets to the Ontario Land & Improvement Company. Its president was Charles Frankish. He founded the
Ontario State Bank in 1887, the settlement's first bank. Central Ontario was incorporated as a city in 1891. In 1901, the original college closed, and a new
Ontario High School replaced it. This soon became
Chaffey College, and offered college courses as well as high school education. Ontario was declared a "model colony" by an act of Congress in 1903. North Ontario broke away from the city in 1906, calling itself
Upland. which was followed by sister station
KOCS-FM in 1947. The stations initially operated as part of The Daily Report, and would go on to change their name, format and ownership many times. In 1960, the higher education part of Chaffey College moved to nearby Rancho Cucamonga. From 1970 to 1980, the
Ontario Motor Speedway hosted motor racing events including the
California 500, and music events like
California Jam. The
Cardenas supermarket chain began in Ontario in 1981.
The Daily Report merged with the nearby
Progress Bulletin to become the
Inland Valley Daily Bulletin in 1990. An
Ontario station of the
Metrolink rail service opened in 1993 (it later became known as "Ontario – East"). Large shopping mall
Ontario Mills opened to the public on November 14, 1996, on the old Ontario Motor Speedway parking lot. On December 13, 1996,
AMC Theatres opened AMC Ontario Mills 30 in Ontario, which it billed as the "world's largest theater". Three months later,
Edwards Theaters opened the Edwards Ontario Palace 22 across the street. At the ShoWest conference in March 1997, Bill Kartozian, the former head of the
National Association of Theatre Owners, told the attendees: "Thou shalt not Ontario each other". In 1999, the large agricultural area in the south of Ontario (the "ag preserve") was rezoned for residential and commercial use. This area was now described as the "New Model Colony", before being renamed
Ontario Ranch, and finally New Haven.
2000s The
University of La Verne opened a law-focused campus in Ontario in 2001. In 2008, the
Ontario Community Events Center opened. It hosts a number of professional minor-league indoor sports teams. Also that year,
West Coast University opened a campus in the city. The headquarters of the
Southern Baptist Convention's Gateway Seminary moved to Ontario in 2016.
Amazon opened their largest United States warehouse in Ontario in 2024. In 2026, a 1.2-million square feet paper warehouse was set on fire by an
arsonist who compared themselves to
Luigi Mangione ==Geography==