Written by Anastacia, Dallas Austin, and Glen Ballard, the song details the singer's strained relationship with her estranged father.

"Left Outside Alone" topped the charts of several countries, including Australia, Austria, the Czech Republic, Italy, Spain, and Switzerland.

AllMusic editor Matthew Chisling wrote "Stronger tracks on the album include "Left Outside Alone,"..., on which Anastacia berates the listener with cries of frustration in pop/rock at its finest.

"[1] Caroline Sullivan of The Guardian wrote "Apparent references pop up: "It's not OK, I don't feel safe," runs the chorus to Left Outside Alone.

"[3] Dom Passantino of Stylus Magazine wrote "Left Outside Alone" starts off as if we're being sang to by the Holy Ghost (assuming Kate Bush is the Father and Tori Amos is the Son), over, yes, exactly the same chords that oversaw "Daredevil"... Then Anastacia switches style back to her normal voice… calling it normal seems a fallacy."

Music editor Dann Ginoe praised the song: "With a high-pitched gothic quiver floating atop ambient brooding, "Left Outside Alone"'s opening strains could easily have her mistaken for Evanescence's Amy Lee.

A different version of the track (entitled "Left Outside Alone, Part 2") appears on the deluxe edition of Anastacia's sixth studio album Resurrection.

[80] British metal band Malevolence recorded a cover as part of The Aggression Sessions split EP[81] released on April 7, 2023.