Timberlake's mother Lynn shared the news herself on Facebook. "My amazing son and his beautiful wife have given us the most precious gift in the world!" she wrote. "Silas Randall Timberlake! Named after my father and my son! Life is beautiful and we couldn't be happier! God bless you all and thanks for all the congrats!"
Us broke news in November that Biel, 33, and the "Suit & Tie" singer, 34, were expecting a little one. "Right now they are just enjoying the news for themselves," an insider told Us at the time. "They just want a happy baby."
Two months later, the doting dad-to-be posted a photo of himself kissing Biel's bare baby bump on his 34th birthday. He gushed: "This year, I'm getting the GREATEST GIFT EVER. CAN'T WAIT."
During Biel's pregnancy, the couple celebrated their two-year anniversary, visited New Zealand, and kept busy working. In February, just days before Biel's 33rd birthday, Timberlake was spotted visiting his love on set of her upcoming film The Devil and the Deep Blue Sea in New Orleans.
The 7th Heaven alum and Timberlake dated on and off for five years before marrying in Italy in October 2012. "It's nice to marry your best friend. It suits me," Timberlake told Ellen DeGeneres in April 2013.
He added: "Every once in a while I can catch a glimpse of her when she doesn't see me looking, and I have this moment where I'm like, 'If you never make a good decision…if you only make bad decisions for the rest of your life. You made one really good decision.'"