[8] Historic occupants of the land along the Rio Hondo River were the indigenous Tongva (also known as Gabrielino), a portion of the Uto-Aztecan family of Native Americans.

When the explorer Juan Rodríguez Cabrillo arrived off the shores of Santa Catalina in 1542, he was met by the Tongva people.

As more non-natives arrived and established settlements, diseases that were endemic among them caused high mortality among the Tongva and other indigenous peoples.

Today the site is near the intersection of San Gabriel Boulevard and the Rio Hondo River.

[11] During the early years of the mission's operations, the region was managed by Spanish colonists who had a "Rancho" land grant system.

The Juan Matias Sanchez Adobe, built in 1844, still stands at the center of old Rancho la Merced in East Montebello.

[6] On January 8, 1847, the Battle of Río San Gabriel took place in what are today parts of the cities of Whittier, Pico Rivera and Montebello.

Two cannons and a plaque commemorating the battle were installed overlooking the river at Bluff Road and Washington Boulevard.

[13] Following the American Civil War, some 5,000 acres (2,000 ha) of the East Los Angeles area was owned by Alessandro Repetto, an Italian immigrant from Genoa, Italy.

Following Repetto's death in 1885, his brother sold his rancho to a consortium of five Los Angeles businessmen, including banker Isaias W. Hellman and wholesale grocer/historian Harris Newmark, for $60,000, or approximately $12 per acre.

[10] The land was later divided among the partners, one large parcel of approximately 2,000 acres (810 ha) going to a partnership of Newmark and his nephew, banker Kaspare Cohn.

After the partners received the advice of hydraulic engineer William Mulholland for the design and building of the town's water system, they subdivided the land.

[14] An area of 200 acres (81 ha) adjacent to the tracks of what was formerly the San Pedro, Los Angeles & Salt Lake Railroad was developed into a townsite called Newmark.

On William Mulholland's suggestion, leaders of the city adopted Montebello as the name in 1920, replacing Newmark.

[15] Originally an agricultural community, the city was known for its prolific production of flowers, berries, fruits, and vegetables.

In honor of Montebello's agricultural roots, the city's official seal contains a red poinsettia in the center.

During World War II, most were interned hundreds of miles away at camps in harsh areas under direction by President Franklin D. Roosevelt by Executive Order 9066.

Many of the displaced residents were unable to return to their homes; survivors and their descendants did not receive an official apology or compensation until the late 20th century.

[10][19] On March 22, 2023, a high-end EF1 tornado struck the city, damaging 17 structures and injuring one person.

According to the National Weather Service, it was the strongest tornado to hit the LA Metro area since March 1983.

Montebello borders East Los Angeles, and is well known for its Mexican-American history and culture.

[50] In the 2010 census, 38.3% of Montebello residents identified as foreign born, with 75.6% speaking a language other than English in the home.

According to the 2010 United States Census, Montebello had a median household income of $47,488, with 15.4% of the population living below the federal poverty line.

Previous Mayor Vanessa Delgado resigned in 2018 to serve on the California State Senate.

[72] The City Council is composed of five members elected at large by the citizens of Montebello to serve for four-year overlapping terms.

serves the city of Montebello, portions of the cities of Bell Gardens, Commerce, Downey, Rosemead, Pico Rivera, and Monterey Park, as well as the unincorporated community of South San Gabriel, and a part of the unincorporated community of East Los Angeles.

Montebello Unified, has made it their goal to ensure students graduate ready and college prepared.

The city is easily accessible to the Long Beach- (I-710), San Gabriel River- (I-605), Pomona- (SR 60) and Santa Ana- (I-5) freeways.

The Crime prevention Bureau provides free security inspections to local businesses and residents.

[66] Montebello has been affiliated with Ashiya, Hyōgo, Japan since the inception of the Sister City Program in 1961.