The KarJenner clan might be going to the wedding of the century … but, they won’t be playing second fiddle to the bride and groom — ’cause they’re already stealing a ton of attention with their fashionable looks!

Kim Kardashian led the group out of a swanky Venetian hotel, slithering through the streets in a gorgeous low-cut, snake-print ensemble … kicking off the festivities for Jeff Bezos and Lauren Sanchez.

KK and her sister Khloé Kardashian — clad in a tight silver-and-black cocktail dress — were throwing up peace signs as they floated down the canal in a little boat while a pal took a pic of them.

While the elder Kardashians stuck to darker colors, Kendall and Kylie Jenner channeled their flowery personalities into their outfits.

Kendall threw on a floral-print outfit that screams Southern European vacay … while Kylie went with a bright yellow outfit that looked molto bene. She sipped on what looks like an Aperol spritz — another European classic.

Celebs have flooded Venice today … with Jeff and Lauren giving a wave while heading to their rehearsal Thursday afternoon.

Everyone from Orlando Bloom, Tom Brady, Scooter Braun, Leonardo DiCaprio and — obviously — the Kardashians are in attendance. And, it’s definitely worth their time … because the couple’s reportedly spending upwards of $50K on each guest in attendance.

BTW … sources told us guests have to give up their phones for this event they’re headed to — so, don’t expect to see the Kardashians sharing a bunch of pics.