| Opera premiere at La Scala in 1887 | 34 |
| Opera premiere: St. Petersburg, 1836 | 36 |
| Opera redone by Elton John and Tim Rice | 39 |
| Opera seen frequently in crosswords | 35 |
| Opera set in Egypt and written by an Italian | 44 |
| Opera set in the age of pharaohs | 32 |
| Opera set in the time of the Pharaohs | 37 |
| Opera set on the banks of the Nile | 34 |
| Opera setting for "Aida" | 34 |
| Opera singer created by Arthur Conan Doyle | 42 |
| Opera singer known as "La Divina" | 43 |
| Opera singer nicknamed "La Divina" | 44 |
| Opera song sung while in the spotlight | 38 |
| Opera song, or a Vegas Strip hotel | 34 |
| Opera star Frances ___: 1883–1952 | 40 |
| Opera subtitled "Wedded Love" | 39 |
| Opera that climaxes with a firing squad | 39 |
| Opera that debuted in Cairo in 1871 | 35 |
| Opera that ends at the Temple of Vulcan | 39 |
| Opera that ends in the Temple of Vulcan | 39 |
| Opera that inspired the T-shirt slogan | 38 |
| Opera that opens on Christmas Eve | 33 |
| Opera that premiered in Cairo in 1871 | 37 |
| Opera that premiered on Christmas Eve of 1871 | 45 |
| Opera title character who dies in a conflagration | 49 |
| Opera title character who drowns | 32 |
| Opera title character who eats a poison leaf | 44 |
| Opera title character who gets dragged into hell | 48 |
| Opera title character who shoots himself | 40 |
| Opera trimmed at both ends by erstwhile actor (9) | 49 |
| Opera with "Ave Maria" | 32 |
| Opera with "O patria mia" | 35 |
| Opera with elephants and Ethiopians | 35 |
| Opera with the aria "Recondita armonia" | 49 |
| Opera with the aria "Vissi d'arte" | 48 |
| Opera with the soprano aria "Ave Maria" | 49 |
| Opera ___ (classical music record label) | 40 |
| Opera ___ (complete works: Lat.) | 32 |
| Opera's "barbiere di qualità " | 46 |
| Opera's "Swedish Nightingale" | 43 |
| Opera's Mario Lanza, for one | 32 |
| Operaman portrayer on "Weekend Update" | 48 |
| Operatic heroine wooed by Beckmesser | 36 |
| Operatic partner of "Pag" | 35 |
| Operatic singer and actress Alberghetti | 39 |
| Operatic spear carrier, for short | 33 |
| Operatic toast of two continents | 32 |
| Operating system between Puma and Panther | 41 |
| Operating system designed by AT&T employees | 47 |
| Operating system developed at Bell Labs | 39 |
| Operating system developed by AT&T originally | 49 |
| Operating system on many Internet servers | 41 |
| Operating system since the '60s | 35 |
| Operating system that doesn't do Windows? | 45 |
| Operating system whose code names are confections | 49 |
| Operating without ___ (taking risks) | 36 |
| Operation Crossroads event, 1946 | 32 |
| Operation Deliberate Force nation | 33 |
| Operation Desert Storm's beginning | 38 |
| Operation Dragoon's loc.: Abbr. | 35 |
| Operation for a new liver or kidney | 35 |
| Operation in "The Sting" | 34 |
| Operation in a medical thriller, for short | 42 |
| Operation Just Cause's setting | 34 |
| Operation Overlord vessel, for short | 36 |
| Operation that often precedes an entrapment claim | 49 |
| Operation __ Freedom (2003-2011 conflict) | 41 |
| Operation ____: naval Antarctica project | 40 |
| Operations were once commonly performed in this | 47 |
| Operator of the MilleMiglia program | 35 |
| Operator of the original N.Y.C. subway | 38 |
| Operator's courteous request | 32 |
| Operators are involved with them | 32 |
| Operetta character whose son is Nanki-Poo | 41 |
| Opeth "Watershed" opener | 34 |
| Ophelia's flower "for thoughts" | 45 |
| Ophthalmic conditions known medically as hordeola | 49 |
| Ophthalmologist's application | 33 |
| Ophthalmologist's diagnosis? | 32 |
| Ophthalmologist's easy diagnosis | 36 |
| Ophthalmologist's favorite film (1981) | 42 |
| Ophthalmologist's prescription | 34 |
| Ophthalmologist's solution, maybe | 37 |
| Opiate often used in cough syrup | 32 |
| Opinion opposed to established views | 36 |
| Opinion piece published at the start of the year? | 49 |
| Opinion protected by the right of free speech | 45 |
| Opp. of ''prescription'' | 40 |
| Oppenheimer's creation, colloquially | 40 |
| Opponent of Deep Blue, IBM's chess computer | 47 |
| Opponent of management, at times | 32 |
| Opponent of Tom and Harry in 1948 | 33 |
| Opponents of defense lawyers: Abbr. | 35 |
| Opponents of the '60s-'70s New Left | 43 |
| Opponents' separator in some sports | 39 |
| Opportunities to run away from home | 35 |
| Opportunity for a football squad | 32 |
| Opportunity for a Hollywood hopeful | 35 |
| Opportunity for a radio talk show caller | 40 |
| Opportunity for a singer or comedian | 36 |