theme song

American  

noun

1. a melody in an operetta or musical comedy so emphasized by repetition as to dominate the presentation.

2. a melody identifying or identified with a radio or television program, dance band, etc., usually played at the beginning of each program.

3. an expression, comment, or subject of conversation that a person or group uses habitually.

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theme song British  

noun

1. a melody used, esp in a film score, to set a mood, introduce a character, etc

2. another term for signature tune

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Etymology

Origin of theme song

An Americanism dating back to 1925–30

Example Sentences

Now a bigger fan than ever, Amanda jokes that the famous theme song makes her have a "little panic attack" at the thought of it happening again.

From BBC • Feb. 22, 2026

I have always found “Raindrops Keep Falling on My Head,” the theme song from the movie “Butch Cassidy and the Sundance Kid,” to be both musically and lyrically cloying.

From The Wall Street Journal • Feb. 5, 2026

The boy said he was trying to think of happy things, at one point singing the "Thomas the Tank Engine" theme song to keep himself going.

From Barron's • Feb. 3, 2026

A typical night can seamlessly bounce from CupcakKe to Robyn, Chappell Roan to Beyoncé and Lady Gaga’s aughts banger “Telephone,” and also “Rivalry,” the show’s theme song by Peter Peter.

From Los Angeles Times • Jan. 18, 2026

I hardly heard her; that theme song synced up with my pounding heartbeat.

From "Hope Springs" by Jaime Berry