Allmusic highlighted the song as one of the most significant post-grunge songs of all time.
"My Happy Ending" was used for the movie Bring It On: All or Nothing.
It was released as the album's second internationally released single in 2004 and became Lavigne's fourth most successful single.
In the United Kingdom, it reached the top five; in the United States, it peaked at number nine (staying in No. 9 for 4 weeks).
Structurally, the song is written in 4/4 style and has a repeated hook in both the chorus and in the intro and outro.