O
- The OC Cafe: the breakfast-and-lunch diner Food & Drink
- October 1973: the great wave's share, measured honestly UFO Sightings
- Odd Fellows: the verified lodges, the Rebekah line, and the floor numbers' gap Lodges & Fraternal Orders
- The official count that names the trade — a named gap, over a tested Osceola absence Fashion
- The oldest possession: the Navarre Cabin, the county's founding object Museums
- Oldest-institution claims, one by one Famous Stories & the Record
- Olling and Ptak, and the Ash Road question: two named gaps, stated exactly Crime & Public Safety
- The Olympians, counted: the roll is zero, by sport and in whole Sports
- On the water and on the bicycle: each tested, each a negative at racing strength Racing
- The one Bitcoin prosecution: the jurisdiction has none seated here Lottery & Crypto
- The one fair on Penn ground: 1852 Fairs
- The one national-series race: Playland Park, 20 July 1952 — a single race, printed as a single race Racing
- The one settler for the whole row, and what this section deliberately did not pull Neighborhoods
- The one-off gatherings that are not here: homecoming, delegation dinner, pageant — tested Osceola Today
- The ones that closed: none after decades here — and the vanishing that never happened Cold Cases
- The open file: Osceola's standing unknowns, and who keeps them Famous Stories & the Record
- The Open-Questions Ledger (L16·10) Sources
- The orders founded here, tested: both foundings are South Bend's; none is this ground's Private Clubs
- The origin ground: fairgrounds racing and the oval inside Playland Park, each dated Racing
- The original plat as paper neighborhood — vacated 1842, alive as a description Neighborhoods
- The Orthodox set tested: no Orthodox seat in town or township; one Mishawaka backyard church, verdicted Churches & Religion
- The Osceola Baseball Softball Association: the town's own ball Sports
- "Osceola Cemetery" — the name in the federal record, the ground unseated Cemeteries
- Osceola Grace Church — the Apple Road congregation Churches & Religion
- The Osceola Music Festival: the town's one standing institution Arts
- “The Osceola Poltergeist” (1966) Famous Stories & the Record
- The Osceola School, 1914 to its demolition Schools
- Osceola Today Section
- “Osceola was founded in 1837” Famous Stories & the Record
- The other interurban, tested separately: only one electric line ever touched this ground Transportation
- The other works of the flagship industries: South Bend's pattern, Osceola's test More Businesses
- The outlying systems and connectors, area by area — and the mountain-bike system as its own system Bike Trails