Supermodel icon Heidi Klum and her model-in-the-making daughter Leni Klum just turned the Festival di Venezia into a full-blown fashion fantasy ... and we’re not sure the red carpet will ever recover.

The dynamic duo stunned at the Venice International Film Festival -- one of the most glamorous film events in the world -- but tonight it felt more like a runway revival ... and the Klums directed all eyes toward their sister-like style.

In a jaw-dropping mother-daughter moment ... Heidi and Leni stepped out in matching corset gowns, Heidi in light pink and Leni in black.

Leni -- proving the apple doesn’t fall far from the stunningly-styled tree -- mirrored her mom in a similar gown, but with slightly different features ... adding her own Gen Z fiery edge.

The pair shared sweet smiles and easy laughs as they posed together, clearly enjoying the age-spanning attention -- Heidi's 52, Leni's 21 -- as much as the fabulous fashion.

And here's the kicker: The duo wasn't even there to promote a project ... but that didn’t stop them from completely stealing the show!