The 39-year-old singer and actor dedicated a sweet post to Biel on Instagram on her birthday Tuesday.
"Happy Birthday to the LOVE of my life..." Timberlake captioned the post. "A new adventure every day and a treasure to me. I can't wait to share many more of these with you. Thanks for putting up with me when I smell funky after a round of golf or, when I smell funky in general. You are the mostest of the mostest, my love! I adore you."
Biel said in a post on her own account that Timberlake threw her a birthday pajama party. She shared a slideshow of photos from the bash that showed her with Timberlake and her birthday cake.
"Celebrating my birthday in style... and by that I mean, in pajamas. I made Justin PROMISE not to sing Happy Birthday to me, so he improvised. Sorry you can't hear it, but I'm still laughing," Biel wrote.
"Thank you, you wonderful human, for really listening to me, and for throwing my kinda party," she told Timberlake. "And thank YOU ALL for the birthday wishes. Feeling the love."
Timberlake and Biel married in October 2012 and have a 4-year-old son, Silas. Timberlake publicly apologized to Biel in December after he was spotted getting close to his Palmer co-star Alisa Wainwright in New Orleans the month prior.
"A few weeks ago I displayed a strong lapse in judgement - but let me be clear - nothing happened between me and my costar," Timberlake wrote on Instagram. "I drank way too much that night and I regret my behavior. This is not the example I want to set for my son."
"I apologize to my amazing wife and family for putting them through such an embarrassing situation, and I am focused on being the best husband and father I can be. This was not that," he said.