WENN 1 / 4

Sarah Lancaster has been keeping a pretty big secret all summer: She's the proud mother of a baby boy!

PHOTOS: More summer pregnancies

The Chuck actress, 31, welcomed son Oliver Michael in L.A. on June 29, her rep confirms to Us Weekly. Weighing in at 8 lbs, 7 oz, this is the first child for Lancaster and attorney Matthew Jacobs.

PHOTOS: What celeb kids eat

The couple tied the knot in Southern California in February. The actress, who plays Ellie on NBC's "Chuck," has appeared in numerous TV shows including "What About Brian," "Everwood" and "Dr. Vegas."

RELATED ON WONDERWALL.COM:

Victoria Beckham debuts her baby at Fashion Week

Is Sandra carrying Ryan's baby?

Which celeb has a stripper mom?