| Online video site | 17 |
| Online video source | 19 |
| Online view intro | 17 |
| Online VIP | 10 |
| Online VIPs | 11 |
| Online voice calling service | 28 |
| Online weekly, e.g. | 19 |
| Online workshop | 15 |
| Online world where people live and pay taxes in 2010, according to Tom Clancy's "Net Force" series | 112 |
| Online yuk | 10 |
| Online zine | 11 |
| Online __ print | 15 |
| Online-only publication | 23 |
| ONLINE? | 7 |
| Onlooker | 8 |
| Onlookers | 9 |
| Only | 4 |
| Only "Garfield" character who doesn't use a speech bubble | 71 |
| Only "Winnie the Pooh" human | 38 |
| Only 20th-century president whose three distinct initials are in alphabetical order | 83 |
| Only 20th-century prez without a coll. degree | 45 |
| Only a bit | 10 |
| Only a bit in debt, perhaps | 27 |
| Only a day away, say | 20 |
| Only a drug of forgetfulness? | 29 |
| Only a few | 10 |
| Only a few get it | 17 |
| Only a few get them | 19 |
| Only a little off | 17 |
| Only a memory | 13 |
| Only a small number | 19 |
| Only a stone's throw away | 29 |
| Only able to think in the short term | 36 |
| Only about 10 percent of it is visible | 38 |
| Only about 10% of it is visible | 31 |
| Only actor to speak in Mel Brooks' "Silent Movie" | 63 |
| Only actor to win a comedy and drama Emmy for the same character | 64 |
| Only Adam and Eve lacked them | 29 |
| Only African-American male to win Wimbledon | 43 |
| Only album attributed to Paul and Linda McCartney | 49 |
| Only American League player to win a batting crown without hitting a home run | 77 |
| Only American Leaguer on the All-Star team every year of the 1950s | 66 |
| Only American star of "Doctor Zhivago" | 48 |
| Only American with more homers than Ruth | 40 |
| Only amount that satisfies the greedy | 37 |
| Only ape to circle the earth | 28 |
| Only as __ resort | 17 |
| Only asteroid visible with the naked eye | 40 |
| Only astrological sign with an inanimate symbol | 47 |
| Only author represented in every major division of the Dewey Decimal System | 75 |
| Only average | 12 |
| Only ballplayer to hit 60 homers in a season three times | 56 |
| Only baseball player to hit a home run in every inning from the first through the 16th | 86 |
| Only batted, briefly | 20 |
| Only Beach Boys #1 hit after 1966 | 33 |
| Only beardless Disney dwarf | 27 |
| Only beardless one of the Seven Dwarfs | 38 |
| Only Beatle who never appeared on "Saturday Night Live" | 65 |
| Only Belarus city with an underground metro | 43 |
| Only Best Director Oscar/Tony/Emmy winner in the same year | 58 |
| Only Bible book that doesn't mention God | 44 |
| Only Billboard hit for the Spanish group Mocedades | 50 |
| Only bird with nostrils on the tip of its beak | 46 |
| Only black child in "South Park" | 42 |
| Only British prime minister of Jewish birth | 43 |
| Only brother not in any Marx Brothers films | 43 |
| Only Canadian major league team, on scoreboards | 47 |
| Only Canadian MLB team | 22 |
| Only Canadian PM with message on the moon | 41 |
| Only cardinal point not in a U.S. state name | 44 |
| Only Central American nation whose official language is English | 63 |
| Only character mentioned in the "Star Wars" crawl | 59 |
| Only character who appeared in every episode of "Star Trek" | 69 |
| Only chess move in which two pieces move on the same turn | 57 |
| Only Chief Justice to have a state funeral | 42 |
| Only child's lack | 21 |
| Only coach to win both N.F.L. and A.F.L. championships | 54 |
| Only common English word from the Finnish | 41 |
| Only common word in the English language with the consecutive letters MPG | 73 |
| Only companion | 14 |
| Only country whose capital starts with "Q": Abbr. | 59 |
| Only country with a non-rectangular flag | 40 |
| Only country without a rectangular flag | 39 |
| Only creature that blushes | 26 |
| Only crime defined in the Constitution | 38 |
| Only daughter of Elizabeth II | 29 |
| Only daughter of Queen Elizabeth II and Prince Philip | 53 |
| Only deer in which both sexes have antlers | 42 |
| Only defenseman in NHL history to have won the scoring title | 60 |
| Only defenseman to lead the NHL in scoring | 42 |
| Only Dolphin quarterback to win a Super Bowl | 44 |
| Only Englishman buried in Arlington | 35 |
| Only Englishman named a Dr. of the Church | 41 |
| Only Englishman to become pope (1154) | 37 |
| Only Englishman to head the Vatican | 35 |
| Only even prime number | 22 |
| Only event in which Venezuela medaled at the 2012 Olympics | 58 |
| Only ex-wife of a U.S. president | 32 |
| Only externally visible part of the central nervous system | 58 |
| Only fair | 9 |