Riverside, California saw a sizeable community of Japanese immigrants contribute to the city's economy by the mind-1890s. Aside from working in the agricultural sector, many Japanese-Americans were business owners within the city.

Between 1895 and 1905, white laborers in Riverside and neighboring cities began attacking Japanese laborers in fear of economic competition. In 1896, Japanese businessman Ulysses Shinsei Kaneko became a naturalized American-citizen. Kaneko's citizenship made him the first Japanese immigrant in the Inland Empire of Southern California to obtain American citizenship.

In 1915, Jukichi Harada, an Issei restaurant owner, challenged the Alien Land Law, which prevented immigrants from owning property. When the state of California attempted to take the property from the Harada family, Harada took them to court, which eventually was escalataed to the California Superior Court under the name "The People of the State of California vs Jukichi Harada." The court decided in favor of Harada, marking a significant event for Japanese immigrants. Harada and his wife Ken died in the Topaz Relocation Center in Utah, where they were forcibly removed to at the beginning of World War II. The Harada House is now listed as a National Historic Landmark.

Before the start of World War II, Japanese-Americans had farms located primarily in the Arlington area and the northern part of Riverside, California. On May 23, 1942, Japanese-Americans living in Riverside were forcibly removed to different incarceration camps in Poston, Arizona, and Manzanar, California. Between March and May of 1942, over 200 Japanese Americans were forcibly removed from Riverside and roughly 180 returned after World War II.

Aside from Japanese influence in Riverside, there were also two Chinatowns built, both of which are now gone. In the late 19th century, Chinese immigrants settled in Riverside and became central to the city's economy. The first Chinatown was located in the downtown area, but was later destroyed by a fire. This then led to the establishment of a second Chinatown in 1885. The second establishment was located in the Tequesquite Arroyo, which held a community of over four hundred Chinese residents. In 1893, the second Chinatown was destroyed by a fire but then rebuilt quickly. By the 1930s, the town's Chinese population was in decline due to the Chinese Exclusion Act of 1882. The last Chinatown resident was Wong Ho Leun, or George Wong.