The singer, who hammed it up with his wife earlier this week at the Vanity Fair Oscar party, took to Instagram on Thursday evening, posting a cute snap of the couple and praising Biel for being the mother and wife she is.
"Happy BAE-DAY, baby!! I can't put into words what you mean to me…" Timberlake, 35, captioned the pic. "You are the GREATEST Mommy and Wife a man could ever ask for. I love you to the MOON and BACK!!! –Your Huz."
In the photo, a scruffy Timberlake kisses Biel – who turns 34 today – on the cheek as the actress, sporting ombréd hair, smiles bright.
Justin Timberlake and Jessica Biel Welcome Son Silas Randall
The couple, who have one child together, 11-month-old son Silas Randall, tied the knot in 2012, after five years of dating and Timberlake has been open about his deep love for her over the years.
"She is the single-handedly most significant person in my life," the crooner told Vanity Fair in 2011. "In my 30 years, she is the most special person … I don't want to say much more, because I have to protect things that are dear to me – for instance, her."
Yes, it's okay to be jealous of these two.