| Oona in ''Chaplin'' | 35 |
| Opaque campaign supporters, briefly | 35 |
| Opaque clouds, to meteorologists | 32 |
| Opaque material used in vases, e.g. | 35 |
| Opaque-glazed earthenware pieces | 32 |
| OPEC foolishness in a Central Park mix-up? | 42 |
| Open a prescription bottle, e.g. | 32 |
| Open area for Robin Hood's men | 34 |
| Open courts used by opera singers? | 34 |
| Open mic night participant, e.g. | 32 |
| Open someone else's e-mails, maybe | 38 |
| Open the front door for, as a guest | 35 |
| Open wide and say "baa" | 33 |
| Open-faced sandwich topped with a fancy spread | 46 |
| Open-mouthed stares from a grouch? | 34 |
| Openable with a gentle push, say | 32 |
| Opened (or closed), as a shot on a set | 38 |
| Opener at an all-Beethoven concert | 34 |
| Opener's next call, in bridge | 33 |
| Opener's second call, in bridge | 35 |
| Opening ... machine ... schedule | 32 |
| Opening allowing entry of air or fluid | 38 |
| Opening day of a PGA event, usually | 35 |
| Opening day of the Masters: Abbr. | 33 |
| Opening for ''sphere'' | 38 |
| Opening for "state" or "net" | 48 |
| Opening for a letter-shaped bolt | 32 |
| Opening for a young baseball fan | 32 |
| Opening for peering through a fence | 35 |
| Opening for the wrist or the back? | 34 |
| Opening in "Hollywood Squares" | 40 |
| Opening in a popular song for kindergartners | 44 |
| Opening in the computer business? | 33 |
| Opening in wastewater management? | 33 |
| Opening line from someone phoning home | 38 |
| Opening line of "Moby-Dork"? | 38 |
| Opening line of a 1966 #1 Beatles hit | 37 |
| Opening maneuver to gain advantage | 34 |
| Opening night expression (with a hidden veggie) | 47 |
| Opening note of "Das Rheingold" | 41 |
| Opening note to "Carmen"? | 35 |
| Opening number of "Hair" | 34 |
| Opening of "A Tale of Two Cities" | 43 |
| Opening of a fuel-burning engine | 32 |
| Opening of a letter to a Baltic capital | 39 |
| Opening of a memorable walrus song | 34 |
| Opening of a sewage-filled pool? | 32 |
| Opening on an environmentalist's agenda? | 44 |
| Opening performance that steals the show, say | 45 |
| Opening routine, when the game is on ice | 40 |
| Opening screen option on many an A.T.M. | 39 |
| Opening to an underground network | 33 |
| Opening used before opening a door | 34 |
| Opening with dexterity or valence | 33 |
| Opening word of "Jabberwocky" | 39 |
| Opening word of "Send in the Clowns" | 46 |
| Opening word of "The Banana Boat Song" | 48 |
| Opening word of "The Waste Land" | 42 |
| Opening word of “Richard III” | 37 |
| Opening word of many an Italian letter | 38 |
| Opening word usually skipped in alphabetizing | 45 |
| Opening words from a TV news reporter | 37 |
| Opening words in a daily journal | 32 |
| Opening words of "A Tale of Two Cities" | 49 |
| Opening words of "Travelin' Man" | 46 |
| Opening words of a 1941 hit song | 32 |
| Opening-night jitters at a famous rock musical? | 47 |
| Openings in the dental profession | 33 |
| Opens a certain type of garment fastener | 40 |
| Opens a tube of toothpaste, e.g. | 32 |
| Opens an envelope at the Oscars, e.g. | 37 |
| Opens up at the doctor's office, perhaps? | 45 |
| Opens up for examination, in a way | 34 |
| Opens, as a change purse, perhaps | 33 |
| Opera "The Golden ---" | 32 |
| Opera "The Tale of ___ Saltan" | 40 |
| Opera ... coloratura ... "Eri tu" | 43 |
| Opera about a hunchbacked jester | 32 |
| Opera about an enslaved Ethiopian girl | 38 |
| Opera about an Ethiopian slave girl | 35 |
| Opera about spellbinding stairs? | 32 |
| Opera based on a Beaumarchais comedy | 36 |
| Opera based on a Shakespeare play | 33 |
| Opera based on two Wedekind plays | 33 |
| Opera boy with 'night visitors' | 39 |
| Opera by today's birthday composer | 38 |
| Opera character who jumps to her death in the end | 49 |
| Opera character who sings "Eri tu" | 44 |
| Opera commissioned by the khedive of Egypt | 42 |
| Opera composer?Donizetti's teacher | 38 |
| Opera fan's opposite of "buffa" | 45 |
| Opera featuring a "grave-digging duet" | 48 |
| Opera featuring a captured princess | 35 |
| Opera featuring Don José and Escamillo | 41 |
| Opera featuring the "Willow Song" | 43 |
| Opera house at Lincoln Center, casually | 39 |
| Opera legend who was close to Onassis | 37 |
| Opera on which "Rent" is based | 40 |
| Opera on which "Rent" was based | 41 |
| Opera performed today, yet neglected | 36 |