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

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.

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.