Jeff Bezos and Lauren Sanchez Bezos are officially back on U.S. soil after their A-list wedding and international travels … ’cause TMZ has learned the newlyweds just popped up in Miami Beach on Tuesday.

The billionaire and his bride enjoyed dinner at AVIV restaurant inside 1 Hotel South Beach … and folks who were there told us it was just Jeff and Lauren at dinner, with security in tow.

No celebrity entourage, friends or family for Jeff and Lauren on this occasion … just a lowkey intimate dinner between husband and wife after rubbing elbows with A-listers at their wedding over in Venice, Italy.

It’s also the first time Jeff and Lauren are back stateside since their wedding of the century overseas … we saw them yachting with a bunch of famous folks after the ceremony, but now it’s on to Florida.

Jeff and Lauren popping up in the MIA makes sense … they have a huge home in the area.