"I'm Sorry" is a 1960 hit song for then-15-year-old American country pop singer Brenda Lee. It peaked at number one on the Billboard Hot 100 singles chart in July 1960. Allmusic guide wrote that it is the pop star's "definitive song", and one of the "finest teen pop songs of its era". It was written by Dub Albritton and Ronnie Self. On the UK Singles Chart, the song peaked at number twelve.

According to the Billboard Book of Number One Hitsby Fred Bronson, Brenda Lee recorded the song early in 1960 but her label, Decca Records, held it from release for several months out of concern that a 15-year-old girl was not mature enough to sing about unrequited love. When the song finally was released, it was considered to be the flip side of the more uptempo "That's All You Gotta Do." Although "That's All You Gotta Do" was a chart success in its own right, reaching number six on the Hot 100, it was "I'm Sorry" that became the smash hit and the standard . On other charts, "I'm Sorry" peaked at number four on the R&B chart and "That's All You Gotta Do" peaked at number nineteen on the R&B charts .

Although it was never released to country radio as a single, "I'm Sorry" would in time become accepted by country fans as a standard of the genre. The song — a fixture on many "country oldies" programs — was an early example of the then-new "Nashville Sound," a style which emphasized a stringed-instrumental sound and background vocals.

Ben Vaughn referenced it in his song "I'm Sorry (But So Is Brenda Lee)".