"Thank you God for blessing us with the most divine gift of our baby son," the proud new mum wrote alongside a photo of her newborn clutching her finger.
"Introducing Bodhi Rain Palmer, born safely, lovingly, and naturally last night. 8lbs even.
Teresa showed off the first picture of her new son Bodhi on her Instagram page
"Bodhi means 'Enlightened One', Rain means 'Abudant Blessings From Above', and we chose Palmer as his last name as Mark's son Isaac didn't take his dad's name either," Teresa explained. "Thanks for all the blessings and love everyone."
The Warm Bodies actress, 27, and director Mark, 33, who were married in Mexico in December, announced their engagement on Twitter in August. Less than two weeks later they confirmed they were expecting their first baby together.
Mark is already a father to son Isaac Love with actress Frankie Shaw.
Teresa with her husband Mark
"This is where my heart is," Teresa tweeted alongside a sonogram picture after revealing her pregnancy news.
"To my precious baby — I'm so blessed to be your mama, we have been wishing for you for awhile. We love you so much and can't wait to kiss your little face and tiny toes. Thank you for hearing our prayers."
She later write to her fans, "Thank you for all the beautiful messages! Those who know me best know that this is something I've been waiting for my whole life. #blessed."