Legend says the name "Tijuana," came from rancho "Tia Juana" (Aunt Jane), but in reality, the name comes from "Tiwan" which means "close to the sea" in the Kumeyaay Indian language, spoken by the Yuman Indian people, hunter-gatherers who lived in this area for centuries before Spanish explorer Cabrillo arrived in 1542. In 1769, Father Junipero Serra founded Alta California's first Spanish mission in San Diego, just north of Tijuana.

After Mexico gained independence from Spain, the governor of Baja California awarded a large land grant to Santiago Arguello, who established a large cattle ranch covering 100 square kilometers here. Land north of Tijuana became part of the United States in 1848, and Tijuana took up its status as an international border town. By 1889, modern Tijuana began to take shape as descendants of Santiago Arguello and Agustín Olvera began to develop the city.

Tijuana has always attracted tourists from across the border, but it first gained international attention during the 1916 San Diego World's Fair, and its pull grew further during the Prohibition Era, when visitors crossed the border in record numbers to drink and gamble. Several casinos were built here in the 1920s, including the luxurious Agua Caliente.

In the 1940s, Mexicans began to relocate to Tijuana for work, and its population tripled between 1940 and 1950. Today, this growing city continues to attract new residents and tourists.