| Orion's bright spot | 23 |
| Orion's Belt unit | 21 |
| Orion's beloved | 19 |
| Orion ___ | 9 |
| Orion neighbor | 14 |
| Orion Mars mission gp. | 22 |
| Orion made love to her | 22 |
| Orion has one | 13 |
| Orion follower | 14 |
| Orion feature | 13 |
| Orioles, Eagles or Cardinals | 28 |
| Orioles' org. | 17 |
| Orioles' manager in 1970 Series win | 39 |
| Orioles' manager | 20 |
| Orioles' home | 17 |
| Orioles' gp. | 16 |
| Orioles' division, with "the" | 43 |
| Orioles' div. | 17 |
| Orioles third baseman Melvin | 28 |
| Orioles team physician? | 23 |
| Orioles start in them | 21 |
| Orioles play here | 17 |
| Orioles pitching coach Mazzone | 30 |
| Orioles owner Peter | 19 |
| Orioles or Santa's reindeer, e.g. | 37 |
| Orioles or Cardinals | 20 |
| Orioles manager Mazzilli | 24 |
| Orioles ironman | 15 |
| Orioles hurler (1966 champs) / Solo crooner of "Oh! My Pa-Pa" (#1 in 1954) | 84 |
| Orioles Hall-of-Fame pitcher who modeled Jockey underwear | 57 |
| Orioles great Ripken | 20 |
| Orioles division | 16 |
| Orioles div. | 12 |
| Orioles catcher Hernández | 28 |
| Orioles and cardinals | 21 |
| Orioles and Blue Jays, informally | 33 |
| Orioles e.g. | 13 |
| Orioles | 7 |
| Oriole-related, e.g. | 20 |
| Oriole, for one | 15 |
| Oriole, e.g., briefly | 21 |
| Oriole's pad | 16 |
| Oriole's origin | 19 |
| Oriole's home, perhaps | 26 |
| Oriole's home | 17 |
| Oriole's hangout | 20 |
| Oriole's distant relative | 29 |
| Oriole's crown? | 19 |
| Oriole's cheer | 18 |
| Oriole's abode | 18 |
| Oriole who played in a record 2,632 straight games | 50 |
| Oriole rival | 12 |
| Oriole Ripken | 13 |
| Oriole Park location | 20 |
| Oriole Park at ___ Yards | 24 |
| Oriole Park at __ Yards | 23 |
| Oriole or Yankee, slangily | 26 |
| Oriole or Yankee, informally | 28 |
| Oriole or Yankee, briefly | 25 |
| Oriole or Tiger, informally | 27 |
| Oriole or Tiger, for short | 26 |
| Oriole or Blue Jay, for short | 29 |
| Oriole or Blue Jay, e.g. | 24 |
| Oriole or Blue Jay, but not a Cardinal | 38 |
| Oriole or Angel | 15 |
| Oriole newcomer | 15 |
| Oriole Hall of Famer | 20 |
| Oriole great Ripken | 19 |
| Oriole color | 12 |
| Oriole catcher: 1955–62 | 30 |
| Oriole : Maryland :: __ : Hawaii | 32 |
| Orinoco, por ejemplo | 20 |
| Orinoco, e.g. | 13 |
| Orinoco y Guadalquivir | 22 |
| Orinoco tributary | 17 |
| Orinoco shocker | 15 |
| Orinoco makeup | 14 |
| Orinoco Flow singer | 22 |
| Orinoco flow | 12 |
| Orinoco feeder | 14 |
| Orinoco contents | 16 |
| Origins of earthquakes | 22 |
| Origins of all people, partially | 32 |
| Origins of a phoenix | 20 |
| Origins Game Fair, e.g. | 23 |
| Origins | 7 |
| Originators of putt-putts | 25 |
| Originators | 11 |
| Originator of the phrase "truth is stranger than fiction" | 67 |
| Originator of the phrase "Pandora's box" | 54 |
| Originator of the phrase "Let the punishment fit the offense" | 71 |
| Originator of the phrase "Familiarity breeds contempt" | 64 |
| Originator of the phlogiston theory | 35 |
| Originator of the occasion celebrated on this date | 50 |
| Originator of the maxim "One swallow does not make a summer" | 70 |
| Originator of the formula e^ix = cos x + i sin x | 48 |
| Originator of the equation e to the power (pi i) + 1 = 0 | 57 |
| Originator of political animals | 31 |
| Originator of Jellicle Cats | 27 |
| Originator of Eur. Common Market | 32 |