The handsome star, 34, is said to have wed the fitness expert at an outdoor ceremony surrounded by family and friends in Santa Barbara, California, yesterday (April 12).
However, one family member was NOT present to witness the lovebirds tie the knot.
Nick's younger brother, Aaron - with whom he has a well-publicisied troubled relationship - was unable to make the romantic occasion after his plane was apparently delayed from Washington DC. Awkward!
Luckily, Nick's bandmate AJ McLean made it on time to help him celebrate his special day.
He wrote on Instagram: "Congrats to my little bro for growing up and finding love. So proud of u bro. Love u both @nickcarter and @laurenkitt."
Nick and Lauren got engaged in February 2013 while on holiday in the Florida Keys. He proposed with a seven-carat pear-shaped diamond ring.
Aspiring actress Lauren posted a photo on Instagram of her and her father last Saturday, writing: "Next Saturday the first man I ever loved will give me away to the love of my life Nick Carter. I love you Dad."
It's already been one hell of a year for Nick. As well as getting married, all five Backstreet Boys have reunited for their In A World Like This tour.
They recently played the London leg of their tour at the O2 Arena, supported by British girl band All Saints.
Do you think Nick Carter and Lauren Kitt make a good couple? Tell us below!
Watch the video to Backstreet Boys' single 'In A World Like This':