'Straight Outta Compton': Cast Not Invited to Oscars ... But Ice Cube Not Interested

The cast of "Straight Outta Compton" will NOT be at the Oscars because they were NOT invited -- nor was the film's producer Ice Cube.

Our 'Compton' sources say none of the cast received an invitation -- mirroring the nomination process. We're told the only people invited are the 2 writers nominated for best original screenplay.

Not that Cube's losing a lot of sleep over it -- we're told he would've RSVP'd a 'No' ... even if he'd been invited.

It's unclear if this is really a diss. There's no public list of Academy members, so it's hard to say what the Academy's criteria are for extending an invite. We've reached out, but no word back yet.

We're told Ice Cube WILL attend the SAG Awards and NAACP Image Awards ... which both nominated 'Compton.'.