| One-person-business owners | 26 |
| One-piece garment: Var. | 23 |
| One-point baccarat card | 23 |
| One-point cribbage knave | 24 |
| One-point score, of a sort | 26 |
| One-point Scrabble letters | 26 |
| One-point Scrabble piece | 24 |
| One-point Scrabble tiles | 24 |
| One-pointer in horseshoes | 25 |
| One-quadrillionth: Comb. form | 29 |
| One-quarter of quadri- | 22 |
| One-quarter of quarante | 23 |
| One-quintillionth: Prefix | 25 |
| One-room house, typically | 25 |
| One-room schoolhouse features | 29 |
| One-room schoolhouse figure | 27 |
| One-room schoolhouse heater | 27 |
| One-round loser to Muhammad | 27 |
| One-seeded fruit, botanically | 29 |
| One-seeded fruit: Var. | 22 |
| One-seeded fruits: Var. | 23 |
| One-seeded, winged fruit | 24 |
| One-seventh of a rainbow | 24 |
| One-seventh of a semana | 23 |
| One-seventh of una semana | 25 |
| One-sixteenth of a cup: Abbr. | 29 |
| One-sixth of a drachma | 22 |
| One-sixth of a fl. oz. | 22 |
| One-sixth of a shilling | 23 |
| One-sixth of dieciocho | 22 |
| One-sixtieth of MMMCXX | 22 |
| One-star hotel attraction | 25 |
| One-story, two-story house | 26 |
| One-stripe soldiers: Abbr. | 26 |
| One-striper, for short | 22 |
| One-stripers, for short | 23 |
| One-syllable Greek letter | 25 |
| One-tenth of a microjoule | 25 |
| One-third of "tri-" | 29 |
| One-third of a 1970 film | 24 |
| One-third of a dollar? | 22 |
| One-third of a film title | 25 |
| One-third of a game win | 23 |
| One-third of a hat trick | 24 |
| One-third of a movie title | 26 |
| One-third of a simple game | 26 |
| One-third of a strikeout? | 25 |
| One-third of a triptych | 23 |
| One-third of a war film | 23 |
| One-third of a war film title | 29 |
| One-third of a wine name | 24 |
| One-third of a WWII film | 24 |
| One-third of some plays | 23 |
| One-thousandth of a yen | 23 |
| One-thousandth of an inch | 25 |
| One-thousandth: Comb. form | 26 |
| One-time Air France plane | 25 |
| One-time Alaskan capital | 24 |
| One-time Argentine leader | 25 |
| One-time AT&T rival | 23 |
| One-time Atlanta arena | 22 |
| One-time bane of childhood | 26 |
| One-time Bauhaus teacher Paul | 29 |
| One-time beaded currency | 24 |
| One-time beauty standard | 24 |
| One-time Blackhawk coach | 24 |
| One-time Brooklyn field | 23 |
| One-time capital of Alaska | 26 |
| One-time capital of Iran | 24 |
| One-time capital of Japan | 25 |
| One-time capital of Moravia | 27 |
| One-time Cardinal Slaughter | 27 |
| One-time change in Rome | 23 |
| One-time charitable home | 24 |
| One-time Chicago slugger | 24 |
| One-time Chinese Chairman | 25 |
| One-time Clinton challenger | 27 |
| One-time Clinton opponent | 25 |
| One-time co-host with Kelly | 27 |
| One-time Colt .45's | 23 |
| One-time Connecticut governor | 29 |
| One-time Cub with a big club | 28 |
| One-time dandy's garb | 25 |
| One-time Delta competitor | 25 |
| One-time Disney bigwig | 22 |
| One-time divorce mecca | 22 |
| One-time DVD player maker | 25 |
| One-time East Asian barrier | 27 |
| One-time econ. measure | 22 |
| One-time econ. yardstick | 24 |
| One-time Edison employee | 24 |
| One-time electronics giant | 26 |
| One-time emperor of Rome | 24 |
| One-time English royal house | 28 |
| One-time female aux. corps | 26 |
| One-time Florentine currency | 28 |
| One-time flying boomers | 23 |
| One-time fourth-largest lake | 28 |
| One-time French protectorate | 28 |
| One-time Genoa magistrates | 26 |