The Pistol Annies singer revealed the news via Instagram and Twitter on Friday, posting a series of pics of her precious family.
"Welcome to the world, love of my life," she wrote. "Dalton William Danks. ❤"
Monroe, 30, and Danks, 32, tied the knot in Walland, Tennessee, on Oct. 24, 2013, with help from Monroe's bandmate and pal, Miranda Lambert. The blond beauty announced she was pregnant last Christmas, captioning a pic of her sonogram, "Best present ever."
"Merry Christmas everyone," she added. "So many new things coming in 2017!! ❤"