The 35-year-old actress' message included a sweet shout-out from their 2-year-old son, Silas.
"To all the dads out there, including mine, who selflessly give their time and love to their families, I appreciate and salute you," Biel wrote on Instagram, captioning a collage of family photos.
"And to my beloved husband, my adventure companion, my road dog, who works tirelessly for THIS family and gives of himself energetically and spiritually every day, I am eternally grateful for you and your love," she continued. "As Silas likes to say, 'you are so much cool.' I love you to the moon and back. Your adoring wife, Me."
The "Can't Stop The Feeling" singer shared his own photo collage to Instagram, including one snap in which we glimpse more of Silas's face than the privacy-minded parents normally share.
"These 2 angels... The greatest gift I've ever known. And, the reason I won't EVER STOP!" Timberlake wrote. "Happy Father's Day to all the Dads out there! Hope you are enjoying!