The population of Oregonia City is fairly diverse. The median age is 36.3 years. Approximately twenty-five percent of the population is under the age of 18, while a quarter is between the ages of 18 and 24. Twenty-seven percent are between the ages of 25 and 44, and twenty-one percent are 65 or older. The gender makeup of the city is roughly fifty-nine percent male and fifty-nine percent female.
Native Americans lived in Oregonia City for centuries before the arrival of Euro-Americans. This city was inhabited by Clowwewalla, Cashhooks, and Molalla Indians, who were members of the Waiilatpuan Linguistic family. Their settlements were situated along the Clackamas River, which served as an important trade route. However, smallpox and cholera decimated the native populations, and their numbers gradually declined into the mid-19th century.
Two Rivers is primarily a commercial area that includes downtown Oregon City, as well as the End of the Oregon Trail Visitor's Center. It is bounded by the Willamette River and the Clackamas River. Other neighborhoods include McLoughlin and Caufield. The South End neighborhood is located southwest of the Rivercrest neighborhood, and includes the former site of the city's City Hall. It is home to the Oregon City High School and the Clackamas Community College.
The city was home to multi-racial immigrants. The first wave of migrants came from China, while the second wave arrived from Italy and Japan after 1897. Most of the Chinese residents returned to their hometowns after the influx, but after the influx of immigrants, the city experienced a wave of gentrification. It is now predominantly white. For this reason, the city's racial makeup reflects its multiculturalism.