'Love Island' Star Alannah Keyser's Dad Defends Her Against Racist Posts

"Love Island USA" bombshell Alannah Keyser is catching major heat online over resurfaced videos showing her allegedly using a racial slur ... but her dad says the outrage is way off base.

Stephane Keyser is coming out swinging in defense of his daughter, telling TMZ there's no world in which Alannah is a racist ... describing her instead as an "educated sweetheart."

Alannah's dad is standing by her in a big way, telling us their family has always had friends from different backgrounds ... which he says makes the hate she's getting all the more ridiculous.

As TMZ previously reported, controversy erupted shortly after Alannah entered the villa Sunday night when an old social media clip resurfaced, appearing to show her using the n-word while singing a song. Another screenshot also appeared to show her using the slur in an IG comment.

The controversy has already sparked a wave of criticism online ... and given "Love Island's" rocky history with race-related scandals, fans are already calling for her to get the boot.