The 35-year-old singer dedicated a sweet post to the actress and mom-of-one in honor of her 34th birthday on March 3.
"Happy BAE-DAY, baby!! I can't put into words what you mean to me... You are the GREATEST Mommy and Wife a man could ever ask for. I love you to the MOON AND BACK!!! -- Your Huz," the star wrote on Instagram.
Timberlake and Biel married in 2012 and welcomed their first child, son Silas Randall, in April. The actress described her ideal date to Entertainment Tonight this week and discussed the importance of keeping romance alive with Extra.
"You have to make it a priority I think no matter what," she said of date nights. "Whether you have kids or don't have kids, you just have to continue to date."
Timberlake and Biel stepped out to attend the Vanity Fair Oscar party Sunday, which the actress called "glamorous" and "really fun." The couple have been together since 2007 and Biel couldn't help but gush about the singer in an interview in September.
"He supports everything that I do and that's why I think he's a wonderful partner," she said on Good Morning America. "We should just be able to talk and laugh and learn together."
Biel is best known for playing Mary Camden on 7th Heaven and will next star in The Devil and the Deep Blue Sea with Jason Sudeikis and Maisie Williams. Timberlake released his fourth studio album, The 20/20 Experience - Part 2, in 2013.