| One-time beauty standard | 24 |
| One-time beaded currency | 24 |
| One-time Bauhaus teacher Paul | 29 |
| One-time bane of childhood | 26 |
| One-time Atlanta arena | 22 |
| One-time AT&T rival | 23 |
| One-time Argentine leader | 25 |
| One-time Alaskan capital | 24 |
| One-time Air France plane | 25 |
| One-thousandth: Comb. form | 26 |
| One-thousandth of an inch | 25 |
| One-thousandth of a yen | 23 |
| One-third of some plays | 23 |
| One-third of a WWII film | 24 |
| One-third of a wine name | 24 |
| One-third of a war film title | 29 |
| One-third of a war film | 23 |
| One-third of a triptych | 23 |
| One-third of a strikeout? | 25 |
| One-third of a simple game | 26 |
| One-third of a movie title | 26 |
| One-third of a hat trick | 24 |
| One-third of a game win | 23 |
| One-third of a film title | 25 |
| One-third of a dollar? | 22 |
| One-third of a 1970 film | 24 |
| One-third of "tri-" | 29 |
| One-tenth of a microjoule | 25 |
| One-syllable Greek letter | 25 |
| One-stripers, for short | 23 |
| One-striper, for short | 22 |
| One-stripe soldiers: Abbr. | 26 |
| One-story, two-story house | 26 |
| One-star hotel attraction | 25 |
| One-sixtieth of MMMCXX | 22 |
| One-sixth of dieciocho | 22 |
| One-sixth of a shilling | 23 |
| One-sixth of a fl. oz. | 22 |
| One-sixth of a drachma | 22 |
| One-sixteenth of a cup: Abbr. | 29 |
| One-seventh of una semana | 25 |
| One-seventh of a semana | 23 |
| One-seventh of a rainbow | 24 |
| One-seeded, winged fruit | 24 |
| One-seeded fruits: Var. | 23 |
| One-seeded fruit: Var. | 22 |
| One-seeded fruit, botanically | 29 |
| One-round loser to Muhammad | 27 |
| One-room schoolhouse heater | 27 |
| One-room schoolhouse figure | 27 |
| One-room schoolhouse features | 29 |
| One-room house, typically | 25 |
| One-quintillionth: Prefix | 25 |
| One-quarter of quarante | 23 |
| One-quarter of quadri- | 22 |
| One-quadrillionth: Comb. form | 29 |
| One-pointer in horseshoes | 25 |
| One-point Scrabble tiles | 24 |
| One-point Scrabble piece | 24 |
| One-point Scrabble letters | 26 |
| One-point score, of a sort | 26 |
| One-point cribbage knave | 24 |
| One-point baccarat card | 23 |
| One-piece garment: Var. | 23 |
| One-person-business owners | 26 |
| One-person performances | 23 |
| One-person performance | 22 |
| One-person opera performances | 29 |
| One-on-one with a big shot | 26 |
| One-on-one Olympic sport | 24 |
| One-on-one gamble, usually | 26 |
| One-on-one fencing sport | 24 |
| One-on-one beneficiary | 22 |
| One-of-a-kind find, to Caesar | 29 |
| One-of-a-kind Dutch cheese? | 27 |
| One-nighters for Jo Anne | 24 |
| One-night stand necessity | 25 |
| One-named western hero | 22 |
| One-named Venetian master | 25 |
| One-named Vegas headliner | 25 |
| One-named Tevye portrayer | 25 |
| One-named Tejano singer | 23 |
| One-named Swedish songstress | 28 |
| One-named Swedish pop singer | 28 |
| One-named sports legend | 23 |
| One-named Spanish singer | 24 |
| One-named Spanish entertainer | 29 |
| One-named Somalian supermodel | 29 |
| One-named Somalian model | 24 |
| One-named Somali model | 22 |
| One-named soccer legend | 23 |
| One-named soccer immortal | 25 |
| One-named singer/actress | 24 |
| One-named singer of the 1960s | 29 |
| One-named singer from Nigeria | 29 |
| One-named singer from Greece | 28 |
| One-named silkscreen designer | 29 |
| One-named rocker/actor | 22 |
| One-named rapper/actress | 24 |
| One-named rapper-turned-actor | 29 |