A whispering gallery is usually a circular, hemispherical, elliptical or ellipsoidal enclosure, often beneath a dome or a vault, in which whispers can be heard clearly in other parts of the gallery. Such galleries can also be set up using two parabolic dishes.

In movies, a "whispering gallery" refers to an architectural phenomenon where the specialized geometry of a dome or curved wall allows a whisper to travel perfectly across a vast space to be heard clearly on the other side. As a cinematic trope, it is often used as a plot device for "secret overhearing." A famous real-world example often seen or referenced in film is the Whispering Gallery in St. Paul’s Cathedral, London, or the one in Grand Central Terminal, New York. In thrillers or period dramas, characters might use the gallery to exchange clandestine information without being seen together, or a protagonist might accidentally overhear a villain’s secret plan because of the focused acoustics. Visually, directors love these locations because they allow for a "split-screen" emotional effect where two characters are physically far apart but aurally intimate. In 2026, with the advent of high-fidelity spatial audio in theaters, these scenes are often engineered to make the audience feel the whisper "traveling" around the cinema walls.