A Night at the Opera was a film starring the Marx Brothers from the early 20th century.
This film was shown during a movie night on the Enterprise in 2153. Sim asked T'Pol to accompany him there, but she refused. (ENT: "Similitude")
Peter Allan Fields, the writer of the Star Trek: Deep Space Nine episode "The Circle", based the scene in Kira's quarters, in which everyone comes to say goodbye to her, on a scene in A Night at the Opera. (Star Trek: Deep Space Nine Companion, p. 80)
A Night at the Opera, according to the Star Trek Encyclopedia, 4th ed., vol. 2, p. 82, was released in 1935.