"You make me laugh. You make me smile. You make me LOVE. You make me want to be BETTER. Speaking of, it doesn't get any BETTER than you," the 36-year-old singer wrote. "Now, I know for sure that it's BETTER to be lucky than good. Ask me who the luckiest guy in the world is and I will tell you that you are looking at him. Happy Birthday, my heart."
Last year, Justin celebrated his wife's 34th birthday with an equally sentimental message and a candid snap.
"Happy BAE-DAY, baby!! I can't put into words what you mean to me," Timberlake wrote, captioning a cute pic of him kissing his wife's cheek. "You are the GREATEST Mommy and Wife a man could ever ask for. I love you to the MOON AND BACK!!!"