The 31-year-old actress and husband Matthew Jacobs welcomed their son Oliver Michael Jacobs on June 29 and he was born in Los Angeles weighing 8lbs 7oz.
In a statement, the couple said to PEOPLE: 'We feel so fortunate for every minute we get to spend with our healthy and happy baby.'
The baby is the first for the couple, who married in Southern California earlier this year.
Lancaster is best known for playing the role of Ellie on the hit NBC TV show.
