Serena Williams and her new husband hopped on a private jet to zip off to their honeymoon ... and he was more than happy to lend a hand.

Serena and Reddit co-founder Alexis Ohanian were spotted loading up Saturday in New Orleans with their baby, Alexis Olympia, in tow. The couple got married 3 days ago in The Big Easy.

It's unclear where the newlyweds and the little one are off to, but if it's anything like their star-studded wedding ... we know the honeymoon will be incredible.