The singer was the subject of an advert on the platform which asked users if they would "rather slap Rihanna or punch Chris Brown".
The ad, which was for a game, appeared to reference Chris Brown's conviction for assaulting Rihanna in 2009 while they were dating.
Snap Inc says the ad "never should have appeared on our service".
Rihanna posted a lengthy comment on an Instagram Story saying she was "trying to figure out what the point was with this mess".
"I'd love to call it ignorance, but I know you ain't that dumb," she wrote.