Jeff Bezos and Lauren Sanchez are in a state of bliss post-wedding, floating like a water taxi through Venice ... and locking lips on a ship as hundreds of photogs snapped pics.

JB and LS were spotted in the city Saturday ... and, they gave paparazzi a show -- full of smiling, waving and, eventually, a big old kiss.

The two are dressed to the nines in the pics ... clearly headed to the next big event of their wedding week.

Lauren also gave a wave while standing on some sort of raised platform -- unclear if it's a balcony, but she looked like royalty in the shot.

Worth noting ... some protesters in Venice were up in arms about Bezos and Sanchez -- both earlier in the week and on Saturday -- so, we don't imagine all the onlookers were cheering for them.

As we told you ... Lauren and Jeff had their official wedding ceremony yesterday on San Grigorio Maggiore -- an island in Venice -- attended by big stars like Sydney Sweeney, Orlando Bloom, Kim Kardashian, Tom Brady and more.

Sources with direct knowledge tell us ... Brady was dancing with everyone at the wedding reception after -- including Sweeney, and Tom's ex Brooks Nader -- and Bloom made the rounds, too.

Ellie Goulding, DJ Kygo and Andrea Bocelli's son, Matteo, all performed at the reception ... and, while the main event broke up around 2 AM, The Gritti Palace -- party central for the week of events -- was popping until well after 3 in the morning, we're told.

Tons of celebs -- including Kylie Jenner and Oprah Winfrey -- are still in town for more wedding events ... including one they're heading to right about now.