| One-run homers | 14 |
| One-round loser to Muhammad | 27 |
| One-room schoolhouse heater | 27 |
| One-room schoolhouse figure | 27 |
| One-room schoolhouse features | 29 |
| One-room pad | 12 |
| One-room house, typically | 25 |
| One-room home | 13 |
| One-room heater | 15 |
| One-room dwelling | 17 |
| One-room apartment | 18 |
| One-room abode | 14 |
| One-quintillionth: Prefix | 25 |
| One-quarter of zero? | 20 |
| One-quarter of tetra- | 21 |
| One-quarter of quarante | 23 |
| One-quarter of quadri- | 22 |
| One-quarter of doce | 19 |
| One-quarter of an H, in Morse code | 34 |
| One-quarter of a mourning lacrosse team? | 40 |
| One-quarter of "Whose woods these are I think I know" | 63 |
| One-quadrillionth: Comb. form | 29 |
| One-principle-for-everything theory | 35 |
| One-pot meals | 13 |
| One-pot meal | 12 |
| One-pot dinners | 15 |
| One-pot dinner | 14 |
| One-pot beef dishes | 19 |
| One-pot beef dish | 17 |
| One-pointers: Abbr. | 19 |
| One-pointers in an outdoor game | 31 |
| One-pointers | 12 |
| One-pointer in horseshoes | 25 |
| One-pointer in Football: Abbr. | 30 |
| One-point throws | 16 |
| One-point Scrabble tiles | 24 |
| One-point Scrabble piece | 24 |
| One-point Scrabble letters | 26 |
| One-point score, of a sort | 26 |
| One-point E, for one | 20 |
| One-point cribbage knave | 24 |
| One-point baccarat card | 23 |
| One-point "Scrabble" tiles | 36 |
| One-pip domino | 14 |
| One-piece, perhaps | 18 |
| One-piece vestments | 19 |
| One-piece swimwear | 18 |
| One-piece swimsuit | 18 |
| One-piece resort wear | 21 |
| One-piece party garb | 20 |
| One-piece outfits | 17 |
| One-piece outfit | 16 |
| One-piece garments, informally | 30 |
| One-piece garments | 18 |
| One-piece garment: Var. | 23 |
| One-piece garment | 17 |
| One-piece cloak | 15 |
| One-piece brand | 15 |
| One-piece bodysuits | 19 |
| One-picture cartoon | 19 |
| One-person-wide line | 20 |
| One-person-business owners | 26 |
| One-person vessels | 18 |
| One-person performances | 23 |
| One-person performance | 22 |
| One-person opera performances | 29 |
| One-person craft | 16 |
| One-person concerts | 19 |
| One-person cab | 14 |
| One-person boats | 16 |
| One-person boat made with animal hides | 38 |
| One-person boat | 15 |
| One-percenter | 13 |
| One-over-par score | 18 |
| One-one, for one | 16 |
| One-one and two-two | 19 |
| One-on-ones | 11 |
| One-on-one with a big shot | 26 |
| One-on-one type | 15 |
| One-on-one test | 15 |
| One-on-one teachers | 19 |
| One-on-one teacher | 18 |
| One-on-one talk | 15 |
| One-on-one student | 18 |
| One-on-one strategy | 19 |
| One-on-one sport | 16 |
| One-on-one scholar | 18 |
| One-on-one pupil | 16 |
| One-on-one Olympic sport | 24 |
| One-on-one offense, in basketball slang | 39 |
| One-on-one meeting, informally | 30 |
| One-on-one meeting | 18 |
| One-on-one learner | 18 |
| One-on-one job for a ladies' man? | 37 |
| One-on-one instructor | 21 |
| One-on-one gamble, usually | 26 |
| One-on-one fighters | 19 |
| One-on-one fight | 16 |
| One-on-one fencing sport | 24 |
| One-on-one exams | 16 |