Jonah Bromwich of "Pitchfork" said the music was "a highlight" and an "oft-disquieting mixtape of golden-age rock n' roll, radio DJ patter, and period-specific commercials." Michael Roffman of "Consequence" said, "The collection is chock full of 60's selections that look strange on paper, but work effortlessly together on screen." Stephen Thomas Erlewine of AllMusic said, "Listening to Once Upon a Time brings that world to life. It's like switching the AM radio on to a 1960s that never faded away." It was nominated for the best compilation soundtrack album for visual media at the 62nd Annual Grammy Awards.