Alba posted a photo on her Instagram Story Sunday, showing her cradling Hayes in her arms. She added a heart over Hayes' face, but it was clear that the 36-year-old actress was wearing black in solidarity with the "Time's Up" initiative.
The Mechanic: Resurrection actress also posted a message of support on Instagram, calling for the end of sexual harassment and supporting gender equality.
"#timesup #equality at home nursing my baby boy wearing a black in solidarity with all who demand equality and respect," Alba wrote.
She included the hashtags #endsexualharassment, #equalpay, #equalrights and #whywewearblack.
Alba and her husband, Cash Warren, celebrated the new year by welcoming their new son, Hayes.
“Hayes Alba Warren 12/31/17 Best gift to ring in the New Year!! Cash and I feel so blessed. Haven and Honor are already obsessed with their new baby bro,” she wrote last week.
Alba and Warren also have two daughters, Haven Garner, 6, and Honor Marie, 9.
Most of the actresses who attended the Globes wore black and a "Time's Up" pin to support the initiative backed by over 300 Hollywood women. The initiative also includes a Legal Defense Fund, which will support women get legal representation in sexual harassment cases. Over $15 million has been raised so far.
When Alba's not acting, she's also leading her Honest Company, which makes eco-friendly baby and skincare products. Unfortunately for Alba, the Wall Street Journal reported last week that sales were flat in 2017, after reaching $300 million in sales in 2016. She launched the company in 2012.
Photo credit: Instagram / @Jessica Alba