| One in the viper family | 23 |
| One in the weasel family | 24 |
| One in the womb with you | 24 |
| One in the woods | 16 |
| One in the woods, so they say | 29 |
| One in top hat and tails | 24 |
| One in training | 15 |
| One in training pants | 21 |
| One in training? | 16 |
| One in twenty-one | 17 |
| One in Venice | 13 |
| One in want | 11 |
| One in Weimar | 13 |
| One in whiteface, maybe | 23 |
| One in with the out-crowd | 25 |
| One in ___ (20%) | 16 |
| One incapable of functioning, slangily | 38 |
| One incapacitated by stress | 27 |
| One inclined to fight | 21 |
| One industry above the rest? | 28 |
| One initiating a call | 21 |
| One inning? | 11 |
| One inside another | 18 |
| One insistent on perfection | 27 |
| One inspired by Calliope | 24 |
| One inspired by Erato | 21 |
| One inspired by Terpsichore | 27 |
| One inspiring love of poetry? | 29 |
| One instructed | 14 |
| One instrumental in history? | 28 |
| One instrumental in music history? | 34 |
| One intentionally not present | 29 |
| One interested in current affairs? | 34 |
| One interested in interest | 26 |
| One interested in net savings? | 30 |
| One interested in possessions | 29 |
| One interested in spreads | 25 |
| One interning | 13 |
| One interpreted by an augur | 27 |
| One interpreting lines | 22 |
| One interrogated | 16 |
| One intimately involved with the spirit world? | 46 |
| One into collecting | 19 |
| One into pain management? | 25 |
| One into the bar scene?: Abbr. | 30 |
| One invested in ministry | 24 |
| One invoked against snakes, for short | 37 |
| One invoked during a drought | 28 |
| One involved in a face-off | 26 |
| One involved in a faceoff | 25 |
| One involved in a pickup | 24 |
| One involved in batting | 23 |
| One involved in bowling balls | 29 |
| One involved in class action? | 29 |
| One involved in foreign exchange? | 33 |
| One involved in future deals? | 29 |
| One involved in globe trotting? | 31 |
| One involved in hand-to-hand combat? | 36 |
| One involved in litigation | 26 |
| One involved in match play? | 27 |
| One involved with drilling: Abbr. | 33 |
| One involved with proofs | 24 |
| One involved with rackets | 25 |
| One involved with turkey stuffing, maybe? | 41 |
| One involved: Suffix | 20 |
| One iota | 8 |
| One iron, in old golf lingo | 27 |
| One irresistible to women | 25 |
| One is ''Come here often?'' | 43 |
| One is "cradled" in answers to asterisked clues | 57 |
| One is "easy as pie" | 30 |
| One is alot | 11 |
| One is anterior, in the brain | 29 |
| One is at either end of Alaska | 30 |
| One is at home | 14 |
| One is called fair | 18 |
| One is depicted in the Emmy statuette | 37 |
| One is dynamic | 14 |
| One is either a "rumpy" or a "stumpy" | 57 |
| One is embraced by a benedict | 29 |
| One is heard in the "1812 Overture" | 45 |
| One is hidden in each of this puzzle's four longest answers | 63 |
| One is hidden in each of today's theme entries | 50 |
| One is in each theme entry | 26 |
| One is in fiscally | 18 |
| One is in the Guinness Book for its 1,728-word vocabulary | 57 |
| One is inclined to use it | 25 |
| One is named after Joe Louis | 28 |
| One is named for the explorer James Ross | 40 |
| One is North, the other South | 29 |
| One is often copped | 19 |
| One is often followed by a verb | 31 |
| One is often said to be dead | 28 |
| One is often seen at the card table | 35 |
| One is often seen near a dessert array | 38 |
| One is often worn above goggles | 31 |
| One is often worn on a uniform | 30 |
| One is on your car | 18 |
| One is one | 10 |
| One is part of a part | 21 |