Cities: O

This index lists 691 U.S. cities and places whose names begin with the letter "O" — every row links to a per-city page showing the ZIP codes, population, household income, and housing data for that municipality. Names are sourced from the U.S. Census Bureau's Gazetteer Files and USPS place data, covering incorporated cities, census-designated places, and unincorporated communities that receive mail under a distinct place name. The alphabetical index above lets you jump directly to any other starting letter; each letter shows its own city count so you can see where the long tail sits (letters like S, C, and M carry the most U.S. place names, while X and Z are sparse).

Sorting is driven by three ACS-backed fields: city name (alphabetical within letter "O"), total population summed across all ZIP codes assigned to the place, and ZIP-code count (how many USPS ZIPs the city is split across). The 26-letter alphabetical index is built dynamically from the underlying cities table — if no cities exist for a given letter, it is grayed out. Pagination caps each page at 50 rows, producing 14 pages for letter "O" alone, which keeps the table fast to render and avoids overwhelming the alphabetical browsing experience.

Each linked city page aggregates Census ACS 2023 5-Year Estimates across every ZIP assigned to that place: median household income, median home value, median rent, owner-occupied share, poverty rate, and unemployment rate — plus a link to the Affordability Dashboard that layers in HUD Fair Market Rents, FBI Uniform Crime Report data, and Department of Labor childcare costs. Use this alphabetical browse when you know a city name but not its state, or when you want to scan a list of similarly named places across the country. All data comes from public federal sources — no editorial ranking, no proprietary scoring.