"I Don't Know Why" (sometimes listed as "I Don't Know Why I Love You") is a 1968 song by American singer-songwriter Stevie Wonder, from the album For Once in My Life (1968). It also serves as the B-side for the 1969 hit "My Cherie Amour". It peaked at No. 39 on the US Billboard Hot 100. The song was recorded when Wonder was 18 years old, and became a moderate hit single, together with "You Met Your Match", another song from the album.
The Jackson 5 cover the song (listed as "Don't Know Why I Love You") on their 1970 album ABC.
Al Kooper covered this song on his album "You Never Know Who Your Friends Are", 1969.
The Rolling Stones released a 1969 cover of the song in 1975 on their ABKCO outtake album Metamorphosis. It was recorded on 3 July 1969 during the sessions for Let It Bleed, the night that news broke of Brian Jones' death.