"My Whole World Ended (The Moment You Left Me)" is the solo debut single for former Temptations lead singer David Ruffin, released on Motown Records in early 1969 (see 1969 in music).

David Ruffin had always been signed as a single artist which was part of the issue with the group who had a collective contract.

The song, with its melody and intro based upon the classical music piece "Frühlingslied" by Felix Mendelssohn, is a bittersweet ballad in the style of "Since I Lost My Baby", "All I Need", "I Could Never Love Another (After Loving You)", "(Loneliness Made Me Realize) It's You That I Need", "(I Know) I'm Losing You" and "I Wish It Would Rain", Ruffin, as the narrator, sings of the extensive pain he has felt since his lover has left him.

All throughout the song, Ruffin asks his lover why she left him, what he did wrong that drove her away, and professes to her that without her, his life is meaningless.

Singing backup for Ruffin on the recording are The Originals, who the same year would score a hit of their own with "Baby I'm For Real".