"Should've Known Better" is a hit song written, composed, and performed by American rock singer Richard Marx. It was released in September 1987 as the second single from his Triple Platinum-selling self-titled debut album. The song peaked at number three on the US Billboard Hot 100 as well as #7 on the Billboard Mainstream Rock Tracks chart in 1987 and #4 on the Radio & Records CHR/Pop Airplay chart. Marx became the first solo artist in recording history to reach the top three of the Billboard Hot 100 with four singles from a debut album.