Taking to social media last night, Zebo shared the news along with a picture of mum and baby.
The couple has named their third newborn son, Noah Anthony Fernandez Zebo.
On Instagram, well wishes from the likes of high profile people such as Amy Huberman, Colin Slade, and Rob Heffernan flooded in.
The 29-year-old Irish rugby star and his longterm partner are already parents to children Jacob and Sofia.
In 2017, Zebo announced his retirement from Munster Rugby but continues to play for Ireland.
In August 2018 he made his debut with French team, Racing 92.
This Saturday, Zebo will make a return to Thomond Park as Racing 92 take on Munster.