| Open someone else's e-mails, maybe | 38 |
| Open mic night participant, e.g. | 32 |
| Open courts used by opera singers? | 34 |
| Open area for Robin Hood's men | 34 |
| Open a prescription bottle, e.g. | 32 |
| OPEC foolishness in a Central Park mix-up? | 42 |
| Opaque-glazed earthenware pieces | 32 |
| Opaque material used in vases, e.g. | 35 |
| Opaque clouds, to meteorologists | 32 |
| Opaque campaign supporters, briefly | 35 |
| Oona in ''Chaplin'' | 35 |
| Oo-la-la leading lady of the 30's | 37 |
| Onto, with ''of'' | 33 |
| Ontario-born hockey legend Bobby | 32 |
| Ontario's St. Lawrence______ | 32 |
| Ontario's second-largest city | 33 |
| Ontario's second most populous city | 39 |
| Ontario's capital, on sports tickers | 40 |
| Ontario's capital, on scoreboards | 37 |
| Ontario's capital, on a scoreboard | 38 |
| Ontario's capital on a sports ticker, | 41 |
| Ontario village and Turkish namesake | 37 |
| Ontario town, or entertainer Cohen | 34 |
| Ontario town whose sign boasts a giant mosquito | 47 |
| Ontario town whose sign boasts a giant elephant | 47 |
| Ontario town or politician Manning | 34 |
| Ontario town and British namesake | 33 |
| Ontario town and French namesake | 33 |
| Ontario port opposite Port Huron, Mich. | 39 |
| Ontario Hockey League team from Erie | 36 |
| Ontario community or the former Taiwan | 38 |
| Ontario community or British namesake | 37 |
| Ontario community or English namesake | 38 |
| Ontario city just west of Buffalo | 33 |
| Ontario cape or former Tory leader Stanfield | 44 |
| Ontario community or Polish namesake | 37 |
| Ont. site of a War of 1812 battle | 33 |
| Onstage extra during an aria, for short | 39 |
| Onslaught of crepe orders at a deli? | 36 |
| Onomatopoeic Sinatra album title | 32 |
| Only X-rated film to win the Best Picture Oscar | 47 |
| Only World Series perfect game pitcher | 38 |
| Only work that Michelangelo signed | 34 |
| Only work of art that Michelangelo signed | 41 |
| Only word heard in a 1958 song of the same name | 47 |
| Only winner of eight consecutive Norris Trophies | 48 |
| Only Wimbledon winner to wear a wig | 35 |
| Only Wimbledon champion to wear a wig | 37 |
| Only when his funny films failed | 32 |
| Only US swimmer to compete in five Olympics | 43 |
| Only US state with two official languages | 41 |
| Only US state with a diamond mine | 33 |
| Only ungulate that mates in the seated position | 47 |
| Only U.S. vice president born in Maryland | 41 |
| Only U.S. state without a rectangular flag | 42 |
| Only U.S. state with a pennant-shaped flag | 42 |
| Only U.S. state whose flag isn't rectangular | 48 |
| Only U.S. president to have three veeps | 39 |
| Only U.S. president born in Hawaii | 34 |
| Only U.N. member whose flag is not rectangular | 46 |
| Only two alphabet letters have them | 35 |
| Only things Noah could afford to take? | 38 |
| Only thing guitarists use w/their feet | 38 |
| Only thing between you and an open window? | 42 |
| Only their queens survive winter | 32 |
| Only the biggest one is at every show | 37 |
| Only the best rockers could also sing this | 42 |
| Only Super Bowl won by the New York Jets | 40 |
| Only Stratego piece with a letter on it | 39 |
| Only Stratego piece that can take a marshal | 43 |
| Only state with two Ivy League schools | 38 |
| Only state with a three-word capital | 36 |
| Only state that borders six states and Canada | 45 |
| Only state never under a foreign flag | 37 |
| Only state capital written with a period | 40 |
| Only state bordered by just one other | 37 |
| Only speaking female in Pooh books | 34 |
| Only soccer player who can throw the ball | 41 |
| Only republic on the Arabian Peninsula | 38 |
| Only reigning pope to write an autobiography | 44 |
| Only recipient of a degree in enigmatology | 42 |
| Only reason to watch the Super Bowl, some say | 45 |
| Only QB to start five Super Bowls | 33 |
| Only president who was also chief justice | 41 |
| Only president to win a Pulitzer | 32 |
| Only President to sit on the Supreme Court | 42 |
| Only president other than LBJ born in Texas | 43 |
| Only president for two nonconsecutive terms | 43 |
| Only president born in New Hampshire | 36 |
| Only player to win Wimbledon as a wild card | 43 |
| Only player to win an MVP in the ABA and NBA | 44 |
| Only player to ever sink an ace in a Skins Game | 47 |
| Only player named MVP in the ABA and NBA | 40 |
| Only planet with exactly one moon | 33 |
| Only place where some ideas look good | 37 |
| Only person to win both an Oscar and a Nobel | 44 |
| Only person to decline the Nobel Peace Prize | 44 |
| Only perfect World Series pitcher | 33 |
| Only other state in Alaska's time zone | 42 |
| Only one-word anagram of a day of the week | 42 |