The rising hip-hop star recently revealed to bosses at GQ magazine he had penned and recorded an emotional ballad for the project, which stars Jamie Foxx, Leonardo DiCaprio and Samuel L. Jackson.
But when production bosses released the track list for the western, Ocean's name was not among those listed as a contributor.
And now Tarantino has opened up about his decision not to use the 25 year old's work, insisting the tune just didn't work with the film.
He tells PitchFork.com, "Frank Ocean wrote a fantastic ballad that was truly lovely and poetic in every way, there just wasn't a scene for it.
"I could have thrown it in quickly just to have it, but that's not why he wrote it and not his intention. So I didn't want to cheapen his effort. But the song is fantastic, and when Frank decides to unleash it on the public, they'll realise it then."
The soundtrack does, however, contain songs from Foxx, rapper Rick Ross, singer John Legend and a mash-up featuring late stars Tupac Shakur and James Brown.